Datasets:

---

codefuse-ai

/

GALLa

like 1

Follow

CodeFuse AI 145

[ 7, 0, 13, 4, 13, 4, 13, 41, 28, 13, 4, 18, 4, 13, 13, 4, 2, 4, 13, 13, 17, 0, 13, 13, 41, 28, 13, 13, 4, 13, 13, 2, 2, 13, 18, 13, 13, 2, 13, 13, 4, 17, 4, 13, 4, 13, 13, 10, 4, 13, 10, 13, 13 ]

[ [ 48, 2 ], [ 10, 9 ], [ 9, 19 ], [ 51, 22 ], [ 52, 30 ], [ 52, 35 ], [ 48, 49 ], [ 51, 52 ] ]

[ "N = int(input())\nA = [int(i) - 1 for i in input().split()]\nprint(len([1 for i, a in enumerate(A) if i == A[a] and i < a]))", "N = int(input())", "N", "int(input())", "int", "input()", "input", "int(i) - 1 for i in input().split()", "for i in input().split()", "i", "input().split()", "().split", "()", "input", "split", "for i in input().split()", "int(i) - 1", "int(i)", "int", "i", "1", "A = [int(i) - 1 for i in input().split()]", "A", "[int(i) - 1 for i in input().split()]", "1 for i, a in enumerate(A) if i == A[a] and i < a", "for i, a in enumerate(A) if i == A[a] and i < a", "i", "a", "enumerate(A)", "enumerate", "A", "i == A[a] and i < a", "i == A[a]", "i", "A[a]", "A", "a", "i < a", "i", "a", "if i == A[a] and i < a", "1", "print(len([1 for i, a in enumerate(A) if i == A[a] and i < a]))", "print", "len([1 for i, a in enumerate(A) if i == A[a] and i < a])", "len", "[1 for i, a in enumerate(A) if i == A[a] and i < a]", "N = int(input())", "int(input())", "N", "A = [int(i) - 1 for i in input().split()]", "[int(i) - 1 for i in input().split()]", "A" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 17, 28, 13, 4, 13, 17, 2, 13, 17, 0, 13, 18, 13, 2, 13, 17, 0, 13, 18, 13, 2, 13, 17, 14, 2, 13, 13, 0, 13, 17, 4, 13, 2, 13, 17, 10, 18, 13, 10, 18, 13, 10, 17, 13, 10, 4, 13, 10, 17, 13, 10, 4, 13 ]

[ [ 72, 2 ], [ 66, 8 ], [ 69, 20 ], [ 24, 23 ], [ 73, 28 ], [ 60, 31 ], [ 67, 33 ], [ 23, 35 ], [ 57, 38 ], [ 67, 40 ], [ 61, 42 ], [ 23, 46 ], [ 58, 47 ], [ 63, 49 ], [ 64, 54 ], [ 70, 54 ], [ 57, 58 ], [ 60, 61 ], [ 63, 64 ], [ 66, 67 ], [ 69, 70 ], [ 72, 73 ] ]

[ "n = int(input())\na = list(map(int, input().split()))\n\nans = 0\nfor i in range(1, (n + 1)):\n like1 = a[i - 1]\n like2 = a[like1 - 1]\n if i == like2:\n ans += 1\nprint(ans // 2)", "n = int(input())", "n", "int(input())", "int", "input()", "input", "a = list(map(int, input().split()))", "a", "list(map(int, input().split()))", "list", "map(int, input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "ans = 0", "ans", "0", "for i in range(1, (n + 1)):\n like1 = a[i - 1]\n like2 = a[like1 - 1]\n if i == like2:\n ans += 1", "i", "range(1, (n + 1))", "range", "1", "n + 1", "n", "1", "like1 = a[i - 1]", "like1", "a[i - 1]", "a", "i - 1", "i", "1", "like2 = a[like1 - 1]", "like2", "a[like1 - 1]", "a", "like1 - 1", "like1", "1", "if i == like2:\n ans += 1", "i == like2", "i", "like2", "ans += 1", "ans", "1", "print(ans // 2)", "print", "ans // 2", "ans", "2", "like2 = a[like1 - 1]", "a[like1 - 1]", "like2", "like1 = a[i - 1]", "a[i - 1]", "like1", "ans += 1", "1", "ans", "a = list(map(int, input().split()))", "list(map(int, input().split()))", "a", "ans = 0", "0", "ans", "n = int(input())", "int(input())", "n" ]

[ 7, 0, 13, 4, 13, 4, 13, 41, 28, 13, 4, 18, 4, 13, 13, 4, 2, 4, 13, 13, 17, 0, 13, 13, 0, 13, 17, 28, 13, 4, 13, 13, 14, 2, 18, 13, 18, 13, 13, 13, 4, 13, 2, 13, 17, 10, 4, 13, 10, 17, 13, 10, 13, 13 ]

[ [ 46, 2 ], [ 10, 9 ], [ 9, 19 ], [ 52, 22 ], [ 49, 25 ], [ 29, 28 ], [ 47, 31 ], [ 53, 35 ], [ 53, 37 ], [ 28, 38 ], [ 28, 39 ], [ 50, 43 ], [ 46, 47 ], [ 49, 50 ], [ 52, 53 ] ]

[ "N = int(input())\nA = [int(a) - 1 for a in input().split()]\nans = 0\nfor i in range(N):\n if A[A[i]] == i: ans += 1\nprint(ans // 2)", "N = int(input())", "N", "int(input())", "int", "input()", "input", "int(a) - 1 for a in input().split()", "for a in input().split()", "a", "input().split()", "().split", "()", "input", "split", "for a in input().split()", "int(a) - 1", "int(a)", "int", "a", "1", "A = [int(a) - 1 for a in input().split()]", "A", "[int(a) - 1 for a in input().split()]", "ans = 0", "ans", "0", "for i in range(N):\n if A[A[i]] == i: ans += 1", "i", "range(N)", "range", "N", "if A[A[i]] == i: ans ", "A[A[i]] == i", "A[A[i]]", "A", "A[i]", "A", "i", "i", "print(ans // 2)", "print", "ans // 2", "ans", "2", "N = int(input())", "int(input())", "N", "ans = 0", "0", "ans", "A = [int(a) - 1 for a in input().split()]", "[int(a) - 1 for a in input().split()]", "A" ]

[ 7, 15, 12, 13, 0, 13, 18, 18, 13, 13, 13, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 17, 28, 13, 4, 13, 13, 14, 2, 18, 13, 2, 18, 13, 13, 17, 2, 13, 17, 0, 13, 17, 4, 13, 2, 13, 17, 14, 2, 13, 17, 4, 13, 17, 4, 13, 10, 12, 13 ]

[ [ 6, 5 ], [ 13, 12 ], [ 5, 16 ], [ 19, 18 ], [ 5, 27 ], [ 31, 30 ], [ 34, 33 ], [ 12, 36 ], [ 18, 40 ], [ 18, 43 ], [ 33, 44 ], [ 33, 47 ], [ 51, 50 ], [ 50, 55 ], [ 30, 55 ], [ 68, 65 ] ]

[ "#!/usr/bin/env python3\n\nfrom sys import stdin, setrecursionlimit\n\n\ndef main():\n input = stdin.buffer.readline\n n = int(input())\n a = list(map(int, input().split()))\n ans = 0\n for i in range(n):\n if a[a[i] - 1] == i + 1:\n ans += 1\n print(ans // 2)\n\n\nif __name__ == \"__main__\":\n setrecursionlimit(10000)\n main()", "from sys import stdin, setrecursionlimit", "def main():\n input = stdin.buffer.readline\n n = int(input())\n a = list(map(int, input().split()))\n ans = 0\n for i in range(n):\n if a[a[i] - 1] == i + 1:\n ans += 1\n print(ans // 2)", "main", "input = stdin.buffer.readline", "input", "stdin.buffer.readline", "stdin.buffer", "stdin", "buffer", "readline", "n = int(input())", "n", "int(input())", "int", "input()", "input", "a = list(map(int, input().split()))", "a", "list(map(int, input().split()))", "list", "map(int, input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "ans = 0", "ans", "0", "for i in range(n):\n if a[a[i] - 1] == i + 1:\n ans += 1\n ", "i", "range(n)", "range", "n", "if a[a[i] - 1] == i + 1:\n ans += 1\n ", "a[a[i] - 1] == i + 1", "a[a[i] - 1]", "a", "a[i] - 1", "a[i]", "a", "i", "1", "i + 1", "i", "1", "ans += 1", "ans", "1", "print(ans // 2)", "print", "ans // 2", "ans", "2", "if __name__ == \"__main__\":\n setrecursionlimit(10000)\n main()", "__name__ == \"__main__\"", "__name__", "\"__main__\"", "setrecursionlimit(10000)", "setrecursionlimit", "10000", "main()", "main", "def main():\n input = stdin.buffer.readline\n n = int(input())\n a = list(map(int, input().split()))\n ans = 0\n for i in range(n):\n if a[a[i] - 1] == i + 1:\n ans += 1\n print(ans // 2)", "def main():\n input = stdin.buffer.readline\n n = int(input())\n a = list(map(int, input().split()))\n ans = 0\n for i in range(n):\n if a[a[i] - 1] == i + 1:\n ans += 1\n print(ans // 2)", "main" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 17, 28, 13, 4, 13, 13, 0, 13, 18, 13, 13, 14, 2, 18, 13, 2, 13, 17, 2, 13, 17, 0, 13, 17, 4, 13, 2, 13, 17, 10, 17, 13, 10, 4, 13, 10, 4, 13, 10, 17, 13, 10, 18, 13 ]

[ [ 57, 2 ], [ 54, 8 ], [ 60, 20 ], [ 24, 23 ], [ 58, 26 ], [ 63, 28 ], [ 55, 30 ], [ 23, 31 ], [ 55, 35 ], [ 64, 37 ], [ 23, 40 ], [ 51, 43 ], [ 52, 48 ], [ 61, 48 ], [ 51, 52 ], [ 54, 55 ], [ 57, 58 ], [ 60, 61 ], [ 63, 64 ] ]

[ "n = int(input())\nal = list(map(int, input().split()))\ncnt = 0\nfor i in range(n):\n tmp = al[i]\n if al[tmp-1] == i+1:\n cnt += 1\n else:\n pass\nprint(cnt//2)", "n = int(input())", "n", "int(input())", "int", "input()", "input", "al = list(map(int, input().split()))", "al", "list(map(int, input().split()))", "list", "map(int, input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "cnt = 0", "cnt", "0", "for i in range(n):\n tmp = al[i]\n if al[tmp-1] == i+1:\n cnt += 1\n else:\n pass", "i", "range(n)", "range", "n", "tmp = al[i]", "tmp", "al[i]", "al", "i", "if al[tmp-1] == i+1:\n cnt += 1\n else:\n pass", "al[tmp-1] == i+1", "al[tmp-1]", "al", "tmp-1", "tmp", "1", "i+1", "i", "1", "cnt += 1", "cnt", "1", "print(cnt//2)", "print", "cnt//2", "cnt", "2", "cnt += 1", "1", "cnt", "al = list(map(int, input().split()))", "list(map(int, input().split()))", "al", "n = int(input())", "int(input())", "n", "cnt = 0", "0", "cnt", "tmp = al[i]", "al[i]", "tmp" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 17, 28, 13, 13, 4, 13, 13, 14, 2, 18, 13, 2, 13, 17, 2, 13, 17, 0, 13, 17, 4, 13, 2, 13, 17, 10, 4, 13, 10, 17, 13, 10, 4, 13, 10, 17, 13 ]

[ [ 47, 2 ], [ 53, 8 ], [ 56, 20 ], [ 54, 27 ], [ 54, 31 ], [ 50, 39 ], [ 51, 44 ], [ 57, 44 ], [ 47, 48 ], [ 50, 51 ], [ 53, 54 ], [ 56, 57 ] ]

[ "N = int(input())\nan = list(map(int, input().split()))\nans = 0\nfor i, a in enumerate(an):\n if an[a-1] == i+1:\n ans += 1\nprint(ans//2)", "N = int(input())", "N", "int(input())", "int", "input()", "input", "an = list(map(int, input().split()))", "an", "list(map(int, input().split()))", "list", "map(int, input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "ans = 0", "ans", "0", "for i, a in enumerate(an):\n if an[a-1] == i+1:\n ans += 1", "i", "a", "enumerate(an)", "enumerate", "an", "if an[a-1] == i+1:\n ans += 1", "an[a-1] == i+1", "an[a-1]", "an", "a-1", "a", "1", "i+1", "i", "1", "ans += 1", "ans", "1", "print(ans//2)", "print", "ans//2", "ans", "2", "N = int(input())", "int(input())", "N", "ans += 1", "1", "ans", "an = list(map(int, input().split()))", "list(map(int, input().split()))", "an", "ans = 0", "0", "ans" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 17, 0, 13, 17, 28, 13, 4, 13, 13, 0, 18, 13, 2, 13, 17, 18, 13, 13, 28, 13, 13, 4, 18, 13, 13, 14, 2, 18, 13, 13, 13, 0, 13, 17, 4, 13, 2, 13, 17, 10, 4, 13, 10, 17, 13, 10, 4, 13, 10, 17, 13, 10, 17, 13 ]

[ [ 61, 2 ], [ 67, 8 ], [ 64, 20 ], [ 73, 23 ], [ 27, 26 ], [ 62, 29 ], [ 36, 31 ], [ 65, 32 ], [ 26, 34 ], [ 68, 37 ], [ 26, 38 ], [ 65, 44 ], [ 65, 49 ], [ 70, 53 ], [ 71, 58 ], [ 74, 58 ], [ 61, 62 ], [ 64, 65 ], [ 67, 68 ], [ 70, 71 ], [ 73, 74 ] ]

[ "N = int(input())\na = list(map(int, input().split()))\npair = {}\nans = 0\nfor i in range(N):\n pair[i + 1] = a[i]\n\nfor key, value in pair.items():\n if pair[value] == key:\n ans += 1\n\nprint(ans // 2)", "N = int(input())", "N", "int(input())", "int", "input()", "input", "a = list(map(int, input().split()))", "a", "list(map(int, input().split()))", "list", "map(int, input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "pair = {}", "pair", "{}", "ans = 0", "ans", "0", "for i in range(N):\n pair[i + 1] = a[i]", "i", "range(N)", "range", "N", "pair[i + 1] = a[i]", "pair[i + 1]", "pair", "i + 1", "i", "1", "a[i]", "a", "i", "for key, value in pair.items():\n if pair[value] == key:\n ans += 1", "key", "value", "pair.items()", "pair.items", "pair", "items", "if pair[value] == key:\n ans += 1", "pair[value] == key", "pair[value]", "pair", "value", "key", "ans += 1", "ans", "1", "print(ans // 2)", "print", "ans // 2", "ans", "2", "N = int(input())", "int(input())", "N", "pair = {}", "{}", "pair", "a = list(map(int, input().split()))", "list(map(int, input().split()))", "a", "ans += 1", "1", "ans", "ans = 0", "0", "ans" ]

[ 7, 12, 13, 0, 13, 4, 13, 4, 13, 41, 28, 13, 4, 18, 4, 13, 13, 4, 4, 13, 13, 0, 13, 13, 0, 13, 17, 28, 13, 4, 13, 13, 14, 2, 2, 13, 17, 18, 13, 2, 18, 13, 13, 17, 0, 13, 17, 4, 13, 2, 13, 17, 14, 2, 13, 17, 4, 13, 10, 12, 13 ]

[ [ 5, 4 ], [ 12, 11 ], [ 11, 20 ], [ 23, 22 ], [ 26, 25 ], [ 29, 28 ], [ 4, 31 ], [ 28, 35 ], [ 22, 38 ], [ 22, 41 ], [ 28, 42 ], [ 46, 45 ], [ 45, 50 ], [ 25, 50 ], [ 60, 57 ] ]

[ "def solve():\n N = int(input())\n A = [int(i) for i in input().split()]\n ans = 0\n for i in range(N):\n if i + 1 == A[A[i] - 1]:\n ans += 1\n print(ans // 2)\n\nif __name__ == \"__main__\":\n solve()", "def solve():\n N = int(input())\n A = [int(i) for i in input().split()]\n ans = 0\n for i in range(N):\n if i + 1 == A[A[i] - 1]:\n ans += 1\n print(ans // 2)", "solve", "N = int(input())", "N", "int(input())", "int", "input()", "input", "int(i) for i in input().split()", "for i in input().split()", "i", "input().split()", "().split", "()", "input", "split", "for i in input().split()", "int(i)", "int", "i", "A = [int(i) for i in input().split()]", "A", "[int(i) for i in input().split()]", "ans = 0", "ans", "0", "for i in range(N):\n if i + 1 == A[A[i] - 1]:\n ans += 1\n ", "i", "range(N)", "range", "N", "if i + 1 == A[A[i] - 1]:\n ans += 1\n ", "i + 1 == A[A[i] - 1]", "i + 1", "i", "1", "A[A[i] - 1]", "A", "A[i] - 1", "A[i]", "A", "i", "1", "ans += 1", "ans", "1", "print(ans // 2)", "print", "ans // 2", "ans", "2", "if __name__ == \"__main__\":\n solve()", "__name__ == \"__main__\"", "__name__", "\"__main__\"", "solve()", "solve", "def solve():\n N = int(input())\n A = [int(i) for i in input().split()]\n ans = 0\n for i in range(N):\n if i + 1 == A[A[i] - 1]:\n ans += 1\n print(ans // 2)", "def solve():\n N = int(input())\n A = [int(i) for i in input().split()]\n ans = 0\n for i in range(N):\n if i + 1 == A[A[i] - 1]:\n ans += 1\n print(ans // 2)", "solve" ]

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[ [ 53, 2 ], [ 56, 8 ], [ 22, 21 ], [ 54, 24 ], [ 57, 30 ], [ 21, 31 ], [ 21, 33 ], [ 57, 37 ], [ 57, 40 ], [ 21, 41 ], [ 21, 44 ], [ 53, 54 ], [ 56, 57 ] ]

[ "N = int(input())\nA = list(map(int, input().split()))\n\nprint([A[i] - 1 > i and A[A[i] - 1] - 1 == i for i in range(N)].count(1))", "N = int(input())", "N", "int(input())", "int", "input()", "input", "A = list(map(int, input().split()))", "A", "list(map(int, input().split()))", "list", "map(int, input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "A[i] - 1 > i and A[A[i] - 1] - 1 == i for i in range(N)", "for i in range(N)", "i", "range(N)", "range", "N", "for i in range(N)", "A[i] - 1 > i and A[A[i] - 1] - 1 == i", "A[i] - 1 > i", "A[i] - 1", "A[i]", "A", "i", "1", "i", "A[A[i] - 1] - 1 == i", "A[A[i] - 1] - 1", "A[A[i] - 1]", "A", "A[i] - 1", "A[i]", "A", "i", "1", "1", "i", "print([A[i] - 1 > i and A[A[i] - 1] - 1 == i for i in range(N)].count(1))", "print", "[A[i] - 1 > i and A[A[i] - 1] - 1 == i for i in range(N)].count(1)", "[A[i] - 1 > i and A[A[i] - 1] - 1 == i for i in range(N)].count", "[A[i] - 1 > i and A[A[i] - 1] - 1 == i for i in range(N)]", "count", "1", "N = int(input())", "int(input())", "N", "A = list(map(int, input().split()))", "list(map(int, input().split()))", "A" ]

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[ [ 49, 2 ], [ 46, 8 ], [ 55, 20 ], [ 47, 27 ], [ 47, 32 ], [ 52, 38 ], [ 53, 43 ], [ 56, 43 ], [ 46, 47 ], [ 49, 50 ], [ 52, 53 ], [ 55, 56 ] ]

[ "n = int(input())\na = list(map(int, input().split()))\ncnt = 0\nfor i, tgt in enumerate(a, 1):\n if a[tgt - 1] == i:\n cnt += 1\nprint(cnt // 2)", "n = int(input())", "n", "int(input())", "int", "input()", "input", "a = list(map(int, input().split()))", "a", "list(map(int, input().split()))", "list", "map(int, input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "cnt = 0", "cnt", "0", "for i, tgt in enumerate(a, 1):\n if a[tgt - 1] == i:\n cnt += 1", "i", "tgt", "enumerate(a, 1)", "enumerate", "a", "1", "if a[tgt - 1] == i:\n cnt += 1", "a[tgt - 1] == i", "a[tgt - 1]", "a", "tgt - 1", "tgt", "1", "i", "cnt += 1", "cnt", "1", "print(cnt // 2)", "print", "cnt // 2", "cnt", "2", "a = list(map(int, input().split()))", "list(map(int, input().split()))", "a", "n = int(input())", "int(input())", "n", "cnt += 1", "1", "cnt", "cnt = 0", "0", "cnt" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 41, 28, 13, 13, 4, 13, 13, 4, 2, 18, 13, 2, 13, 17, 2, 13, 17, 4, 13, 2, 4, 13, 13, 17, 10, 4, 13, 10, 4, 13 ]

[ [ 44, 2 ], [ 47, 8 ], [ 48, 25 ], [ 48, 29 ], [ 44, 45 ], [ 47, 48 ] ]

[ "N = int(input())\na = list(map(int, input().split()))\nprint(sum([a[x-1]==i+1 for i,x in enumerate(a)])//2)", "N = int(input())", "N", "int(input())", "int", "input()", "input", "a = list(map(int, input().split()))", "a", "list(map(int, input().split()))", "list", "map(int, input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "a[x-1]==i+1 for i,x in enumerate(a)", "for i,x in enumerate(a)", "i", "x", "enumerate(a)", "enumerate", "a", "for i,x in enumerate(a)", "a[x-1]==i+1", "a[x-1]", "a", "x-1", "x", "1", "i+1", "i", "1", "print(sum([a[x-1]==i+1 for i,x in enumerate(a)])//2)", "print", "sum([a[x-1]==i+1 for i,x in enumerate(a)])//2", "sum([a[x-1]==i+1 for i,x in enumerate(a)])", "sum", "[a[x-1]==i+1 for i,x in enumerate(a)]", "2", "N = int(input())", "int(input())", "N", "a = list(map(int, input().split()))", "list(map(int, input().split()))", "a" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 41, 28, 13, 4, 13, 17, 2, 13, 17, 4, 13, 0, 13, 13, 0, 13, 17, 28, 13, 4, 13, 13, 14, 2, 18, 13, 13, 18, 13, 2, 18, 13, 13, 17, 0, 13, 17, 0, 18, 13, 13, 17, 4, 13, 13, 10, 4, 13, 10, 17, 13, 10, 17, 13, 10, 4, 13, 10, 13, 13 ]

[ [ 65, 2 ], [ 74, 8 ], [ 22, 21 ], [ 66, 26 ], [ 21, 29 ], [ 77, 31 ], [ 68, 34 ], [ 38, 37 ], [ 66, 40 ], [ 78, 44 ], [ 37, 45 ], [ 75, 47 ], [ 57, 49 ], [ 75, 50 ], [ 37, 51 ], [ 71, 54 ], [ 60, 57 ], [ 75, 58 ], [ 37, 59 ], [ 72, 63 ], [ 69, 63 ], [ 65, 66 ], [ 68, 69 ], [ 71, 72 ], [ 74, 75 ], [ 77, 78 ] ]

[ "n = int(input())\nA = list(map(int,input().split()))\nB = [i for i in range(1,n+1)]\ncnt = 0\nfor i in range(n):\n if B[i]==A[(A[i]-1)]:\n cnt+=1\n A[i]=0\nprint(cnt) ", "n = int(input())", "n", "int(input())", "int", "input()", "input", "A = list(map(int,input().split()))", "A", "list(map(int,input().split()))", "list", "map(int,input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "i for i in range(1,n+1)", "for i in range(1,n+1)", "i", "range(1,n+1)", "range", "1", "n+1", "n", "1", "for i in range(1,n+1)", "i", "B = [i for i in range(1,n+1)]", "B", "[i for i in range(1,n+1)]", "cnt = 0", "cnt", "0", "for i in range(n):\n if B[i]==A[(A[i]-1)]:\n cnt+=1\n A[i]=0", "i", "range(n)", "range", "n", "if B[i]==A[(A[i]-1)]:\n cnt+=1\n A[i]=0", "B[i]==A[(A[i]-1)]", "B[i]", "B", "i", "A[(A[i]-1)]", "A", "A[i]-1", "A[i]", "A", "i", "1", "cnt+=1", "cnt", "1", "A[i]=0", "A[i]", "A", "i", "0", "print(cnt)", "print", "cnt", "n = int(input())", "int(input())", "n", "cnt = 0", "0", "cnt", "cnt+=1", "1", "cnt", "A = list(map(int,input().split()))", "list(map(int,input().split()))", "A", "B = [i for i in range(1,n+1)]", "[i for i in range(1,n+1)]", "B" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 41, 28, 13, 4, 13, 17, 2, 13, 17, 4, 13, 0, 13, 13, 0, 13, 39, 28, 13, 4, 13, 13, 4, 18, 13, 13, 39, 18, 13, 13, 18, 13, 13, 0, 13, 17, 28, 13, 4, 13, 13, 14, 2, 2, 18, 18, 13, 13, 17, 18, 18, 13, 2, 18, 18, 13, 13, 17, 17, 17, 2, 18, 18, 13, 13, 17, 18, 18, 13, 2, 18, 18, 13, 13, 17, 17, 17, 0, 13, 17, 4, 13, 2, 13, 17, 10, 13, 13, 10, 17, 13, 10, 4, 13, 10, 39, 13, 10, 17, 13, 10, 4, 13 ]

[ [ 120, 2 ], [ 111, 8 ], [ 22, 21 ], [ 121, 26 ], [ 21, 29 ], [ 105, 31 ], [ 114, 34 ], [ 38, 37 ], [ 121, 40 ], [ 115, 43 ], [ 112, 47 ], [ 37, 48 ], [ 106, 50 ], [ 37, 51 ], [ 108, 53 ], [ 57, 56 ], [ 121, 59 ], [ 115, 65 ], [ 56, 66 ], [ 115, 70 ], [ 115, 74 ], [ 56, 75 ], [ 115, 82 ], [ 56, 83 ], [ 115, 87 ], [ 115, 91 ], [ 56, 92 ], [ 117, 97 ], [ 118, 102 ], [ 109, 102 ], [ 105, 106 ], [ 108, 109 ], [ 111, 112 ], [ 114, 115 ], [ 117, 118 ], [ 120, 121 ] ]

[ "N=int(input())\na=list(map(int,input().split()))\nI=[i for i in range (1,N+1)]\nb=[]\nfor i in range(N):\n b.append([a[i],I[i]])\ncount=0\nfor i in range(N):\n if b[i][0]==b[b[i][0]-1][1] and b[i][1]==b[b[i][0]-1][0]:\n count+=1\nprint(count//2)", "N=int(input())", "N", "int(input())", "int", "input()", "input", "a=list(map(int,input().split()))", "a", "list(map(int,input().split()))", "list", "map(int,input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "i for i in range (1,N+1)", "for i in range (1,N+1)", "i", "range (1,N+1)", "range", "1", "N+1", "N", "1", "for i in range (1,N+1)", "i", "I=[i for i in range (1,N+1)]", "I", "[i for i in range (1,N+1)]", "b=[]", "b", "[]", "for i in range(N):\n b.append([a[i],I[i]])", "i", "range(N)", "range", "N", "b.append([a[i],I[i]])", "b.append", "b", "append", "[a[i],I[i]]", "a[i]", "a", "i", "I[i]", "I", "i", "count=0", "count", "0", "for i in range(N):\n if b[i][0]==b[b[i][0]-1][1] and b[i][1]==b[b[i][0]-1][0]:\n count+=1", "i", "range(N)", "range", "N", "if b[i][0]==b[b[i][0]-1][1] and b[i][1]==b[b[i][0]-1][0]:\n count+=1", "b[i][0]==b[b[i][0]-1][1] and b[i][1]==b[b[i][0]-1][0]", "b[i][0]==b[b[i][0]-1][1]", "b[i][0]", "[i]", "b", "i", "0", "b[b[i][0]-1][1]", "[b[i][0]-1]", "b", "b[i][0]-1", "b[i][0]", "[i]", "b", "i", "0", "1", "1", "b[i][1]==b[b[i][0]-1][0]", "b[i][1]", "[i]", "b", "i", "1", "b[b[i][0]-1][0]", "[b[i][0]-1]", "b", "b[i][0]-1", "b[i][0]", "[i]", "b", "i", "0", "1", "0", "count+=1", "count", "1", "print(count//2)", "print", "count//2", "count", "2", "I=[i for i in range (1,N+1)]", "[i for i in range (1,N+1)]", "I", "count=0", "0", "count", "a=list(map(int,input().split()))", "list(map(int,input().split()))", "a", "b=[]", "[]", "b", "count+=1", "1", "count", "N=int(input())", "int(input())", "N" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 17, 0, 13, 17, 28, 13, 4, 13, 13, 14, 2, 2, 18, 13, 13, 13, 2, 18, 13, 18, 13, 13, 2, 13, 17, 4, 13, 13, 10, 4, 13, 10, 4, 13, 10, 17, 13, 10, 17, 13 ]

[ [ 50, 2 ], [ 53, 8 ], [ 56, 20 ], [ 59, 23 ], [ 27, 26 ], [ 51, 29 ], [ 54, 34 ], [ 26, 35 ], [ 57, 36 ], [ 57, 39 ], [ 54, 41 ], [ 26, 42 ], [ 26, 44 ], [ 60, 48 ], [ 50, 51 ], [ 53, 54 ], [ 56, 57 ], [ 59, 60 ] ]

[ "n = int(input())\na = list(map(int, input().split()))\n\nd = {}\nans = 0\nfor i in range(n):\n if a[i] in d and d[a[i]] == i+1: ans += 1\n else: d[i+1] = a[i]\nprint(ans)", "n = int(input())", "n", "int(input())", "int", "input()", "input", "a = list(map(int, input().split()))", "a", "list(map(int, input().split()))", "list", "map(int, input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "d = {}", "d", "{}", "ans = 0", "ans", "0", "for i in range(n):\n if a[i] in d and d[a[i]] == i+1: ans += 1\n else: d[i+1] = a[i]", "i", "range(n)", "range", "n", "if a[i] in d and d[a[i]] == i+1: ans += 1\n else: d[i+1] = a[i]", "a[i] in d and d[a[i]] == i+1", "a[i] in d", "a[i]", "a", "i", "d", "d[a[i]] == i+1", "d[a[i]]", "d", "a[i]", "a", "i", "i+1", "i", "1", "print(ans)", "print", "ans", "n = int(input())", "int(input())", "n", "a = list(map(int, input().split()))", "list(map(int, input().split()))", "a", "d = {}", "{}", "d", "ans = 0", "0", "ans" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 17, 28, 13, 4, 13, 13, 14, 2, 18, 13, 2, 18, 13, 13, 17, 2, 13, 17, 0, 13, 17, 4, 13, 4, 13, 2, 13, 17, 10, 4, 13, 10, 17, 13, 10, 4, 13, 10, 17, 13 ]

[ [ 50, 2 ], [ 56, 8 ], [ 59, 20 ], [ 24, 23 ], [ 51, 26 ], [ 57, 30 ], [ 57, 33 ], [ 23, 34 ], [ 23, 37 ], [ 53, 40 ], [ 54, 47 ], [ 60, 47 ], [ 50, 51 ], [ 53, 54 ], [ 56, 57 ], [ 59, 60 ] ]

[ "n = int(input())\na = list(map(int,input().split()))\ncount = 0\nfor i in range(n):\n if(a[a[i]-1] == i+1):\n count += 1\nprint(int(count/2))", "n = int(input())", "n", "int(input())", "int", "input()", "input", "a = list(map(int,input().split()))", "a", "list(map(int,input().split()))", "list", "map(int,input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "count = 0", "count", "0", "for i in range(n):\n if(a[a[i]-1] == i+1):\n count += 1", "i", "range(n)", "range", "n", "if(a[a[i]-1] == i+1):\n count += 1", "a[a[i]-1] == i+1", "a[a[i]-1]", "a", "a[i]-1", "a[i]", "a", "i", "1", "i+1", "i", "1", "count += 1", "count", "1", "print(int(count/2))", "print", "int(count/2)", "int", "count/2", "count", "2", "n = int(input())", "int(input())", "n", "count += 1", "1", "count", "a = list(map(int,input().split()))", "list(map(int,input().split()))", "a", "count = 0", "0", "count" ]

[ 7, 0, 13, 4, 13, 4, 13, 41, 28, 13, 4, 18, 4, 13, 13, 4, 4, 13, 13, 0, 13, 2, 39, 17, 13, 0, 13, 17, 28, 13, 4, 13, 17, 2, 13, 17, 14, 2, 18, 13, 18, 13, 13, 13, 0, 13, 17, 4, 13, 2, 13, 17, 10, 17, 13, 10, 2, 13, 10, 17, 13, 10, 4, 13 ]

[ [ 62, 2 ], [ 10, 9 ], [ 9, 18 ], [ 56, 20 ], [ 59, 26 ], [ 30, 29 ], [ 63, 34 ], [ 57, 39 ], [ 57, 41 ], [ 29, 42 ], [ 29, 43 ], [ 53, 45 ], [ 54, 50 ], [ 60, 50 ], [ 53, 54 ], [ 56, 57 ], [ 59, 60 ], [ 62, 63 ] ]

[ "n = int (input())\nA = [None] + [int(x) for x in input().split()]\n\nans = 0\nfor i in range(1, n+1):\n if A[A[i]] == i:\n ans += 1\nprint(ans //2)", "n = int (input())", "n", "int (input())", "int", "input()", "input", "int(x) for x in input().split()", "for x in input().split()", "x", "input().split()", "().split", "()", "input", "split", "for x in input().split()", "int(x)", "int", "x", "A = [None] + [int(x) for x in input().split()]", "A", "[None] + [int(x) for x in input().split()]", "[None]", "None", "[int(x) for x in input().split()]", "ans = 0", "ans", "0", "for i in range(1, n+1):\n if A[A[i]] == i:\n ans += 1", "i", "range(1, n+1)", "range", "1", "n+1", "n", "1", "if A[A[i]] == i:\n ans += 1", "A[A[i]] == i", "A[A[i]]", "A", "A[i]", "A", "i", "i", "ans += 1", "ans", "1", "print(ans //2)", "print", "ans //2", "ans", "2", "ans += 1", "1", "ans", "A = [None] + [int(x) for x in input().split()]", "[None] + [int(x) for x in input().split()]", "A", "ans = 0", "0", "ans", "n = int (input())", "int (input())", "n" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 17, 28, 13, 4, 13, 13, 0, 13, 18, 13, 13, 14, 2, 2, 18, 13, 2, 13, 17, 17, 13, 0, 13, 17, 4, 13, 2, 13, 17, 10, 17, 13, 10, 4, 13, 10, 4, 13, 10, 17, 13, 10, 18, 13 ]

[ [ 57, 2 ], [ 54, 8 ], [ 60, 20 ], [ 24, 23 ], [ 58, 26 ], [ 63, 28 ], [ 55, 30 ], [ 23, 31 ], [ 55, 36 ], [ 64, 38 ], [ 23, 41 ], [ 51, 43 ], [ 52, 48 ], [ 61, 48 ], [ 51, 52 ], [ 54, 55 ], [ 57, 58 ], [ 60, 61 ], [ 63, 64 ] ]

[ "N = int(input())\nA = list(map(int, input().split()))\ncount = 0\nfor x in range(N):\n find = A[x]\n if A[find - 1] - 1 == x:\n count += 1\nprint(count // 2)", "N = int(input())", "N", "int(input())", "int", "input()", "input", "A = list(map(int, input().split()))", "A", "list(map(int, input().split()))", "list", "map(int, input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "count = 0", "count", "0", "for x in range(N):\n find = A[x]\n if A[find - 1] - 1 == x:\n count += 1", "x", "range(N)", "range", "N", "find = A[x]", "find", "A[x]", "A", "x", "if A[find - 1] - 1 == x:\n count += 1", "A[find - 1] - 1 == x", "A[find - 1] - 1", "A[find - 1]", "A", "find - 1", "find", "1", "1", "x", "count += 1", "count", "1", "print(count // 2)", "print", "count // 2", "count", "2", "count += 1", "1", "count", "A = list(map(int, input().split()))", "list(map(int, input().split()))", "A", "N = int(input())", "int(input())", "N", "count = 0", "0", "count", "find = A[x]", "A[x]", "find" ]

[ 7, 15, 13, 0, 13, 4, 13, 4, 13, 0, 13, 4, 18, 4, 13, 13, 0, 13, 4, 18, 4, 18, 13, 13, 13, 13, 13, 0, 13, 17, 28, 13, 13, 4, 13, 13, 14, 2, 18, 13, 2, 13, 17, 2, 13, 17, 0, 13, 2, 13, 17, 4, 13, 2, 13, 17, 10, 2, 13, 10, 17, 13, 10, 4, 13, 10, 4, 13, 10, 4, 13 ]

[ [ 66, 4 ], [ 69, 10 ], [ 63, 17 ], [ 70, 24 ], [ 60, 28 ], [ 64, 35 ], [ 70, 35 ], [ 64, 39 ], [ 70, 39 ], [ 57, 47 ], [ 61, 49 ], [ 58, 49 ], [ 58, 54 ], [ 61, 54 ], [ 57, 58 ], [ 60, 61 ], [ 63, 64 ], [ 66, 67 ], [ 69, 70 ] ]

[ "import numpy as np\nN = int(input())\na = input().split()\na = np.array(a).astype(int)\ncount = 0\nfor i,ai in enumerate(a):\n \n if a[ai-1] == i+1:\n count = count + 1\nprint(count//2)", "import numpy as np", "numpy", "N = int(input())", "N", "int(input())", "int", "input()", "input", "a = input().split()", "a", "input().split()", "().split", "()", "input", "split", "a = np.array(a).astype(int)", "a", "np.array(a).astype(int)", "np.array(a).astype", "np.array(a)", "np.array", "np", "array", "a", "astype", "int", "count = 0", "count", "0", "for i,ai in enumerate(a):\n \n if a[ai-1] == i+1:\n count = count + 1", "i", "ai", "enumerate(a)", "enumerate", "a", "if a[ai-1] == i+1:\n count = count + 1", "a[ai-1] == i+1", "a[ai-1]", "a", "ai-1", "ai", "1", "i+1", "i", "1", "count = count + 1", "count", "count + 1", "count", "1", "print(count//2)", "print", "count//2", "count", "2", "count = count + 1", "count + 1", "count", "count = 0", "0", "count", "a = np.array(a).astype(int)", "np.array(a).astype(int)", "a", "N = int(input())", "int(input())", "N", "a = input().split()", "input().split()", "a" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 17, 41, 28, 13, 4, 13, 2, 13, 17, 4, 17, 0, 13, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 28, 13, 4, 13, 13, 0, 18, 13, 2, 13, 17, 18, 13, 13, 28, 13, 4, 13, 17, 2, 13, 17, 14, 2, 18, 13, 18, 13, 13, 13, 0, 13, 17, 4, 13, 2, 13, 17, 10, 17, 13, 10, 13, 13, 10, 17, 13, 10, 4, 13, 10, 4, 13 ]

[ [ 86, 2 ], [ 74, 8 ], [ 13, 12 ], [ 87, 16 ], [ 77, 21 ], [ 83, 24 ], [ 37, 36 ], [ 87, 39 ], [ 46, 41 ], [ 78, 42 ], [ 36, 44 ], [ 84, 47 ], [ 36, 48 ], [ 51, 50 ], [ 87, 55 ], [ 78, 60 ], [ 78, 62 ], [ 50, 63 ], [ 50, 64 ], [ 80, 66 ], [ 81, 71 ], [ 75, 71 ], [ 74, 75 ], [ 77, 78 ], [ 80, 81 ], [ 83, 84 ], [ 86, 87 ] ]

[ "n = int(input())\nans = 0\nflag = [-1 for i in range(n+1)]\nA = list(map(int,input().split()))\nfor i in range(n):\n flag[i+1] = A[i]\nfor i in range(1,n+1):\n if flag[flag[i]] == i:\n ans += 1\nprint(ans//2)", "n = int(input())", "n", "int(input())", "int", "input()", "input", "ans = 0", "ans", "0", "-1 for i in range(n+1)", "for i in range(n+1)", "i", "range(n+1)", "range", "n+1", "n", "1", "for i in range(n+1)", "-1", "flag = [-1 for i in range(n+1)]", "flag", "[-1 for i in range(n+1)]", "A = list(map(int,input().split()))", "A", "list(map(int,input().split()))", "list", "map(int,input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "for i in range(n):\n flag[i+1] = A[i]", "i", "range(n)", "range", "n", "flag[i+1] = A[i]", "flag[i+1]", "flag", "i+1", "i", "1", "A[i]", "A", "i", "for i in range(1,n+1):\n if flag[flag[i]] == i:\n ans += 1", "i", "range(1,n+1)", "range", "1", "n+1", "n", "1", "if flag[flag[i]] == i:\n ans += 1", "flag[flag[i]] == i", "flag[flag[i]]", "flag", "flag[i]", "flag", "i", "i", "ans += 1", "ans", "1", "print(ans//2)", "print", "ans//2", "ans", "2", "ans = 0", "0", "ans", "flag = [-1 for i in range(n+1)]", "[-1 for i in range(n+1)]", "flag", "ans += 1", "1", "ans", "A = list(map(int,input().split()))", "list(map(int,input().split()))", "A", "n = int(input())", "int(input())", "n" ]

[ 7, 15, 13, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 4, 18, 13, 13, 13, 0, 13, 2, 13, 17, 0, 13, 17, 28, 13, 4, 13, 13, 14, 2, 13, 18, 13, 18, 13, 13, 0, 13, 17, 4, 13, 2, 13, 17, 10, 17, 13, 10, 2, 13, 10, 4, 13, 10, 4, 13, 10, 17, 13, 10, 4, 13 ]

[ [ 64, 4 ], [ 73, 10 ], [ 67, 22 ], [ 74, 27 ], [ 61, 29 ], [ 68, 31 ], [ 74, 31 ], [ 70, 34 ], [ 38, 37 ], [ 65, 40 ], [ 37, 43 ], [ 62, 45 ], [ 68, 45 ], [ 74, 45 ], [ 62, 47 ], [ 68, 47 ], [ 74, 47 ], [ 37, 48 ], [ 58, 50 ], [ 59, 55 ], [ 71, 55 ], [ 58, 59 ], [ 61, 62 ], [ 64, 65 ], [ 67, 68 ], [ 70, 71 ], [ 73, 74 ] ]

[ "import numpy as np\nN = int(input())\n\na = list(map(int, input().split()))\na = np.array(a)\na = a - 1\n\ncnt = 0\n\nfor i in range(N):\n if i == a[a[i]]:\n cnt += 1\n\nprint(cnt//2)", "import numpy as np", "numpy", "N = int(input())", "N", "int(input())", "int", "input()", "input", "a = list(map(int, input().split()))", "a", "list(map(int, input().split()))", "list", "map(int, input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "a = np.array(a)", "a", "np.array(a)", "np.array", "np", "array", "a", "a = a - 1", "a", "a - 1", "a", "1", "cnt = 0", "cnt", "0", "for i in range(N):\n if i == a[a[i]]:\n cnt += 1", "i", "range(N)", "range", "N", "if i == a[a[i]]:\n cnt += 1", "i == a[a[i]]", "i", "a[a[i]]", "a", "a[i]", "a", "i", "cnt += 1", "cnt", "1", "print(cnt//2)", "print", "cnt//2", "cnt", "2", "cnt += 1", "1", "cnt", "a = a - 1", "a - 1", "a", "N = int(input())", "int(input())", "N", "a = np.array(a)", "np.array(a)", "a", "cnt = 0", "0", "cnt", "a = list(map(int, input().split()))", "list(map(int, input().split()))", "a" ]

[ 7, 0, 13, 4, 13, 13, 4, 18, 4, 18, 4, 13, 17, 13, 13, 31, 13, 4, 13, 2, 4, 13, 2, 2, 13, 17, 18, 13, 2, 18, 13, 13, 17, 17, 10, 4, 13 ]

[ [ 35, 2 ], [ 35, 15 ], [ 35, 36 ] ]

[ "n,*a=map(int,open(0).read().split())\nprint(sum(i+1==a[a[i]-1] for i in range(n))//2)", "n,*a=map(int,open(0).read().split())", "n", "map(int,open(0).read().split())", "map", "int", "open(0).read().split()", "(0).read().split", "(0).read()", "(0).read", "(0)", "open", "0", "read", "split", "*a", "a", "print(sum(i+1==a[a[i]-1] for i in range(n))//2)", "print", "sum(i+1==a[a[i]-1] for i in range(n))//2", "sum(i+1==a[a[i]-1] for i in range(n))", "sum", "i+1==a[a[i]-1]", "i+1", "i", "1", "a[a[i]-1]", "a", "a[i]-1", "a[i]", "a", "i", "1", "2", "n,*a=map(int,open(0).read().split())", "map(int,open(0).read().split())", "n" ]

[ 7, 15, 13, 0, 13, 18, 18, 13, 13, 13, 4, 18, 13, 13, 2, 17, 17, 0, 13, 4, 13, 4, 13, 0, 13, 2, 39, 17, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 17, 28, 13, 13, 4, 13, 13, 14, 2, 13, 17, 9, 14, 2, 13, 18, 13, 13, 0, 13, 17, 4, 13, 2, 13, 17, 10, 2, 13, 10, 17, 13, 10, 4, 13, 10, 17, 13, 10, 18, 13 ]

[ [ 79, 4 ], [ 73, 18 ], [ 80, 22 ], [ 67, 24 ], [ 80, 36 ], [ 76, 39 ], [ 68, 46 ], [ 68, 56 ], [ 70, 59 ], [ 71, 64 ], [ 77, 64 ], [ 67, 68 ], [ 70, 71 ], [ 73, 74 ], [ 76, 77 ], [ 79, 80 ] ]

[ "import sys\ninput = sys.stdin.readline\nsys.setrecursionlimit(10 ** 7)\n\nn = int(input())\na = [0] + list(map(int, input().split()))\n\nans = 0\nfor i, v in enumerate(a):\n if i == 0:\n continue\n if i == a[v]:\n ans += 1\nprint(ans // 2)", "import sys", "sys", "input = sys.stdin.readline", "input", "sys.stdin.readline", "sys.stdin", "sys", "stdin", "readline", "sys.setrecursionlimit(10 ** 7)", "sys.setrecursionlimit", "sys", "setrecursionlimit", "10 ** 7", "10", "7", "n = int(input())", "n", "int(input())", "int", "input()", "input", "a = [0] + list(map(int, input().split()))", "a", "[0] + list(map(int, input().split()))", "[0]", "0", "list(map(int, input().split()))", "list", "map(int, input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "ans = 0", "ans", "0", "for i, v in enumerate(a):\n if i == 0:\n continue\n if i == a[v]:\n ans += 1", "i", "v", "enumerate(a)", "enumerate", "a", "if i == 0:\n continue\n ", "i == 0", "i", "0", "continue", "if i == a[v]:\n ans += 1", "i == a[v]", "i", "a[v]", "a", "v", "ans += 1", "ans", "1", "print(ans // 2)", "print", "ans // 2", "ans", "2", "a = [0] + list(map(int, input().split()))", "[0] + list(map(int, input().split()))", "a", "ans += 1", "1", "ans", "n = int(input())", "int(input())", "n", "ans = 0", "0", "ans", "input = sys.stdin.readline", "sys.stdin.readline", "input" ]

[ 7, 15, 13, 12, 13, 29, 4, 13, 4, 13, 12, 13, 29, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 12, 13, 0, 13, 4, 13, 29, 4, 13, 18, 13, 39, 4, 13, 13, 12, 13, 29, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 4, 13, 0, 13, 4, 13, 0, 13, 39, 17, 0, 13, 13, 0, 13, 17, 28, 13, 4, 13, 17, 2, 13, 17, 14, 2, 2, 18, 13, 18, 13, 13, 13, 2, 18, 13, 13, 17, 0, 13, 17, 4, 13, 2, 13, 17, 10, 12, 13, 10, 12, 13, 10, 13, 13, 10, 12, 13, 10, 4, 13, 10, 12, 13, 10, 17, 13, 10, 39, 13, 10, 4, 13, 10, 17, 13 ]

[ [ 27, 26 ], [ 26, 33 ], [ 26, 37 ], [ 110, 50 ], [ 99, 52 ], [ 122, 54 ], [ 102, 56 ], [ 119, 58 ], [ 104, 62 ], [ 123, 63 ], [ 116, 65 ], [ 69, 68 ], [ 111, 73 ], [ 105, 79 ], [ 120, 79 ], [ 105, 81 ], [ 120, 81 ], [ 68, 82 ], [ 68, 83 ], [ 105, 86 ], [ 120, 86 ], [ 68, 87 ], [ 125, 90 ], [ 126, 95 ], [ 117, 95 ], [ 123, 104 ], [ 104, 105 ], [ 110, 111 ], [ 116, 117 ], [ 119, 120 ], [ 122, 123 ], [ 125, 126 ] ]

[ "# For taking integer inputs.\nimport math\n\n\ndef inp():\n return(int(input()))\n\n\n# For taking List inputs.\ndef inlist():\n return(list(map(int, input().split())))\n\n\n# For taking string inputs. Actually it returns a List of Characters, instead of a string, which is easier to use in Python, because in Python, Strings are Immutable.\ndef instr():\n s = input()\n return(list(s[:len(s)]))\n\n\n# For taking space seperated integer variable inputs.\ndef invr():\n return(map(int, input().split()))\n\n\nn = inp()\n\na = inlist()\nb = [0]\nb += a\np = 0\nfor i in range(1, n+1):\n if b[b[i]] == i and b[i] > 0:\n p += 1\n\n\nprint(p//2)", "import math", "math", "def inp():\n return(int(input()))\n\n\n# For taking List inputs.", "inp", "return(int(input()))", "int(input())", "int", "input()", "input", "def inlist():\n return(list(map(int, input().split())))\n\n\n# For taking string inputs. Actually it returns a List of Characters, instead of a string, which is easier to use in Python, because in Python, Strings are Immutable.", "inlist", "return(list(map(int, input().split())))", "list(map(int, input().split()))", "list", "map(int, input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "def instr():\n s = input()\n return(list(s[:len(s)]))\n\n\n# For taking space seperated integer variable inputs.", "instr", "s = input()", "s", "input()", "input", "return(list(s[:len(s)]))", "list(s[:len(s)])", "list", "s[:len(s)]", "s", ":len(s)", "len(s)", "len", "s", "def invr():\n return(map(int, input().split()))", "invr", "return(map(int, input().split()))", "map(int, input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "n = inp()", "n", "inp()", "inp", "a = inlist()", "a", "inlist()", "inlist", "b = [0]", "b", "[0]", "0", "b += a", "b", "a", "p = 0", "p", "0", "for i in range(1, n+1):\n if b[b[i]] == i and b[i] > 0:\n p += 1", "i", "range(1, n+1)", "range", "1", "n+1", "n", "1", "if b[b[i]] == i and b[i] > 0:\n p += 1", "b[b[i]] == i and b[i] > 0", "b[b[i]] == i", "b[b[i]]", "b", "b[i]", "b", "i", "i", "b[i] > 0", "b[i]", "b", "i", "0", "p += 1", "p", "1", "print(p//2)", "print", "p//2", "p", "2", "def inp():\n return(int(input()))\n\n\n# For taking List inputs.", "def inp():\n return(int(input()))\n\n\n# For taking List inputs.", "inp", "def inlist():\n return(list(map(int, input().split())))\n\n\n# For taking string inputs. Actually it returns a List of Characters, instead of a string, which is easier to use in Python, because in Python, Strings are Immutable.", "def inlist():\n return(list(map(int, input().split())))\n\n\n# For taking string inputs. Actually it returns a List of Characters, instead of a string, which is easier to use in Python, because in Python, Strings are Immutable.", "inlist", "b += a", "a", "b", "def invr():\n return(map(int, input().split()))", "def invr():\n return(map(int, input().split()))", "invr", "n = inp()", "inp()", "n", "def instr():\n s = input()\n return(list(s[:len(s)]))\n\n\n# For taking space seperated integer variable inputs.", "def instr():\n s = input()\n return(list(s[:len(s)]))\n\n\n# For taking space seperated integer variable inputs.", "instr", "p = 0", "0", "p", "b = [0]", "[0]", "b", "a = inlist()", "inlist()", "a", "p += 1", "1", "p" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 17, 0, 13, 17, 28, 13, 13, 0, 13, 17, 14, 2, 18, 13, 2, 13, 17, 13, 0, 13, 17, 4, 13, 2, 13, 17, 10, 17, 13, 10, 17, 13, 10, 4, 13, 10, 4, 13, 10, 17, 13, 10, 17, 13 ]

[ [ 57, 2 ], [ 54, 8 ], [ 51, 20 ], [ 48, 23 ], [ 27, 26 ], [ 55, 26 ], [ 60, 29 ], [ 55, 34 ], [ 26, 36 ], [ 61, 38 ], [ 49, 38 ], [ 63, 40 ], [ 64, 45 ], [ 52, 45 ], [ 48, 49 ], [ 51, 52 ], [ 54, 55 ], [ 57, 58 ], [ 60, 61 ], [ 63, 64 ] ]

[ "n = int(input())\nA = list(map(int, input().split()))\n\nans = 0\ncnt = 0\n\nfor a in A:\n cnt += 1\n if A[a-1] == cnt:\n ans += 1\n\nprint(ans//2)", "n = int(input())", "n", "int(input())", "int", "input()", "input", "A = list(map(int, input().split()))", "A", "list(map(int, input().split()))", "list", "map(int, input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "ans = 0", "ans", "0", "cnt = 0", "cnt", "0", "for a in A:\n cnt += 1\n if A[a-1] == cnt:\n ans += 1", "a", "A", "cnt += 1", "cnt", "1", "if A[a-1] == cnt:\n ans += 1", "A[a-1] == cnt", "A[a-1]", "A", "a-1", "a", "1", "cnt", "ans += 1", "ans", "1", "print(ans//2)", "print", "ans//2", "ans", "2", "cnt = 0", "0", "cnt", "ans = 0", "0", "ans", "A = list(map(int, input().split()))", "list(map(int, input().split()))", "A", "n = int(input())", "int(input())", "n", "cnt += 1", "1", "cnt", "ans += 1", "1", "ans" ]

[ 7, 15, 13, 15, 13, 0, 13, 17, 0, 13, 4, 13, 4, 13, 41, 28, 13, 4, 18, 4, 13, 13, 4, 4, 13, 13, 0, 13, 13, 28, 13, 4, 13, 13, 14, 2, 13, 2, 18, 13, 2, 18, 13, 13, 17, 17, 0, 13, 17, 4, 13, 4, 13, 2, 13, 17, 10, 17, 13, 10, 4, 13, 10, 13, 13, 10, 17, 13 ]

[ [ 66, 6 ], [ 60, 9 ], [ 17, 16 ], [ 16, 25 ], [ 63, 27 ], [ 31, 30 ], [ 61, 33 ], [ 30, 36 ], [ 64, 39 ], [ 64, 42 ], [ 30, 43 ], [ 57, 47 ], [ 58, 54 ], [ 67, 54 ], [ 57, 58 ], [ 60, 61 ], [ 63, 64 ], [ 66, 67 ] ]

[ "import math\nimport copy\n\nneko = 0\nn = int(input())\na = [int(x) for x in input().split()]\nfor i in range(n):\n if i == a[a[i]-1]-1:\n neko += 1\nprint(int(neko/2))", "import math", "math", "import copy", "copy", "neko = 0", "neko", "0", "n = int(input())", "n", "int(input())", "int", "input()", "input", "int(x) for x in input().split()", "for x in input().split()", "x", "input().split()", "().split", "()", "input", "split", "for x in input().split()", "int(x)", "int", "x", "a = [int(x) for x in input().split()]", "a", "[int(x) for x in input().split()]", "for i in range(n):\n if i == a[a[i]-1]-1:\n neko += 1", "i", "range(n)", "range", "n", "if i == a[a[i]-1]-1:\n neko += 1", "i == a[a[i]-1]-1", "i", "a[a[i]-1]-1", "a[a[i]-1]", "a", "a[i]-1", "a[i]", "a", "i", "1", "1", "neko += 1", "neko", "1", "print(int(neko/2))", "print", "int(neko/2)", "int", "neko/2", "neko", "2", "neko += 1", "1", "neko", "n = int(input())", "int(input())", "n", "a = [int(x) for x in input().split()]", "[int(x) for x in input().split()]", "a", "neko = 0", "0", "neko" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 12, 2, 4, 13, 13, 17, 23, 4, 18, 4, 13, 13, 0, 13, 17, 28, 13, 4, 13, 13, 14, 2, 18, 13, 18, 13, 13, 13, 0, 13, 17, 4, 13, 2, 13, 17, 10, 4, 13, 10, 4, 13, 10, 17, 13, 10, 17, 13 ]

[ [ 53, 2 ], [ 50, 8 ], [ 59, 26 ], [ 30, 29 ], [ 54, 32 ], [ 51, 36 ], [ 51, 38 ], [ 29, 39 ], [ 29, 40 ], [ 56, 42 ], [ 57, 47 ], [ 60, 47 ], [ 50, 51 ], [ 53, 54 ], [ 56, 57 ], [ 59, 60 ] ]

[ "N = int(input())\na = list(map(lambda x:int(x)-1,input().split()))\nans = 0\nfor i in range(N):\n if a[a[i]] == i:\n ans += 1\nprint(ans//2)", "N = int(input())", "N", "int(input())", "int", "input()", "input", "a = list(map(lambda x:int(x)-1,input().split()))", "a", "list(map(lambda x:int(x)-1,input().split()))", "list", "map(lambda x:int(x)-1,input().split())", "map", "lambda x:int(x)-1", "int(x)-1", "int(x)", "int", "x", "1", "x", "input().split()", "().split", "()", "input", "split", "ans = 0", "ans", "0", "for i in range(N):\n if a[a[i]] == i:\n ans += 1", "i", "range(N)", "range", "N", "if a[a[i]] == i:\n ans += 1", "a[a[i]] == i", "a[a[i]]", "a", "a[i]", "a", "i", "i", "ans += 1", "ans", "1", "print(ans//2)", "print", "ans//2", "ans", "2", "a = list(map(lambda x:int(x)-1,input().split()))", "list(map(lambda x:int(x)-1,input().split()))", "a", "N = int(input())", "int(input())", "N", "ans += 1", "1", "ans", "ans = 0", "0", "ans" ]

[ 7, 0, 31, 13, 4, 13, 13, 4, 18, 4, 18, 4, 13, 17, 13, 13, 0, 13, 17, 28, 13, 13, 4, 13, 13, 0, 13, 2, 2, 18, 13, 39, 13, 2, 13, 17, 39, 13, 2, 13, 17, 4, 13, 2, 13, 17, 10, 2, 13, 10, 17, 13 ]

[ [ 4, 2 ], [ 50, 17 ], [ 47, 26 ], [ 48, 44 ], [ 51, 44 ], [ 47, 48 ], [ 50, 51 ] ]

[ "*a, = map(int, open(0).read().split())\nc = 0\nfor i, j in enumerate(a):\n c += (a[j:j+1] == [i])*(i > 0)\nprint(c // 2)", "*a, = map(int, open(0).read().split())", "*a", "a", "map(int, open(0).read().split())", "map", "int", "open(0).read().split()", "(0).read().split", "(0).read()", "(0).read", "(0)", "open", "0", "read", "split", "c = 0", "c", "0", "for i, j in enumerate(a):\n c += (a[j:j+1] == [i])*(i > 0)", "i", "j", "enumerate(a)", "enumerate", "a", "c += (a[j:j+1] == [i])*(i > 0)", "c", "(a[j:j+1] == [i])*(i > 0)", "a[j:j+1] == [i]", "a[j:j+1]", "a", "j:j+1", "j", "j+1", "j", "1", "[i]", "i", "i > 0", "i", "0", "print(c // 2)", "print", "c // 2", "c", "2", "c += (a[j:j+1] == [i])*(i > 0)", "(a[j:j+1] == [i])*(i > 0)", "c", "c = 0", "0", "c" ]

[ 7, 15, 13, 15, 13, 15, 13, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 17, 28, 13, 13, 4, 13, 13, 14, 2, 18, 13, 2, 13, 17, 2, 13, 17, 0, 13, 17, 4, 13, 2, 13, 17, 10, 4, 13, 10, 4, 13, 10, 17, 13, 10, 17, 13 ]

[ [ 53, 8 ], [ 56, 14 ], [ 62, 26 ], [ 57, 33 ], [ 57, 37 ], [ 59, 45 ], [ 60, 50 ], [ 63, 50 ], [ 53, 54 ], [ 56, 57 ], [ 59, 60 ], [ 62, 63 ] ]

[ "#!/usr/bin/env python3\nimport collections\nimport itertools as it\nimport math\n#import numpy as np\n \n# = input()\nn = int(input())\n# = map(int, input().split())\na = list(map(int, input().split()))\n# = [int(input()) for i in range(N)]\n#\n# c = collections.Counter()\n\nans_ = 0\nfor i, a_ in enumerate(a):\n if a[a_-1] == i + 1: \n ans_ += 1\nprint(ans_ // 2)", "import collections", "collections", "import itertools as it", "itertools", "import math", "math", "n = int(input())", "n", "int(input())", "int", "input()", "input", "a = list(map(int, input().split()))", "a", "list(map(int, input().split()))", "list", "map(int, input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "ans_ = 0", "ans_", "0", "for i, a_ in enumerate(a):\n if a[a_-1] == i + 1: \n ans_ += 1", "i", "a_", "enumerate(a)", "enumerate", "a", "if a[a_-1] == i + 1: \n ans_ += 1", "a[a_-1] == i + 1", "a[a_-1]", "a", "a_-1", "a_", "1", "i + 1", "i", "1", "ans_ += 1", "ans_", "1", "print(ans_ // 2)", "print", "ans_ // 2", "ans_", "2", "n = int(input())", "int(input())", "n", "a = list(map(int, input().split()))", "list(map(int, input().split()))", "a", "ans_ += 1", "1", "ans_", "ans_ = 0", "0", "ans_" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 17, 28, 13, 4, 13, 13, 14, 2, 18, 13, 2, 18, 13, 13, 17, 2, 13, 17, 0, 13, 17, 0, 18, 13, 13, 17, 4, 13, 13, 10, 17, 13, 10, 4, 13, 10, 17, 13, 10, 4, 13 ]

[ [ 54, 2 ], [ 60, 8 ], [ 51, 20 ], [ 24, 23 ], [ 55, 26 ], [ 61, 30 ], [ 43, 32 ], [ 61, 33 ], [ 23, 34 ], [ 23, 37 ], [ 57, 40 ], [ 46, 43 ], [ 61, 44 ], [ 23, 45 ], [ 58, 49 ], [ 52, 49 ], [ 51, 52 ], [ 54, 55 ], [ 57, 58 ], [ 60, 61 ] ]

[ "N = int(input())\nl = list(map(int, input().split()))\n\ncounter = 0\n\nfor i in range(N):\n if l[l[i]-1] == i+1:\n counter += 1\n l[i] = -99\nprint(counter)", "N = int(input())", "N", "int(input())", "int", "input()", "input", "l = list(map(int, input().split()))", "l", "list(map(int, input().split()))", "list", "map(int, input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "counter = 0", "counter", "0", "for i in range(N):\n if l[l[i]-1] == i+1:\n counter += 1\n l[i] = -99", "i", "range(N)", "range", "N", "if l[l[i]-1] == i+1:\n counter += 1\n l[i] = -99", "l[l[i]-1] == i+1", "l[l[i]-1]", "l", "l[i]-1", "l[i]", "l", "i", "1", "i+1", "i", "1", "counter += 1", "counter", "1", "l[i] = -99", "l[i]", "l", "i", "-99", "print(counter)", "print", "counter", "counter = 0", "0", "counter", "N = int(input())", "int(input())", "N", "counter += 1", "1", "counter", "l = list(map(int, input().split()))", "list(map(int, input().split()))", "l" ]

[ 7, 12, 13, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 17, 28, 13, 4, 13, 13, 14, 2, 18, 13, 2, 18, 13, 13, 17, 2, 13, 17, 0, 13, 17, 4, 13, 2, 13, 17, 4, 13, 10, 12, 13 ]

[ [ 5, 4 ], [ 11, 10 ], [ 23, 22 ], [ 26, 25 ], [ 4, 28 ], [ 10, 32 ], [ 10, 35 ], [ 25, 36 ], [ 25, 39 ], [ 43, 42 ], [ 42, 47 ], [ 22, 47 ], [ 53, 50 ] ]

[ "def resolve():\n N = int(input())\n a = list(map(int, input().split()))\n ans = 0\n for i in range(N):\n if a[a[i]-1] == i+1:\n ans += 1\n print(ans//2)\nresolve()", "def resolve():\n N = int(input())\n a = list(map(int, input().split()))\n ans = 0\n for i in range(N):\n if a[a[i]-1] == i+1:\n ans += 1\n print(ans//2)", "resolve", "N = int(input())", "N", "int(input())", "int", "input()", "input", "a = list(map(int, input().split()))", "a", "list(map(int, input().split()))", "list", "map(int, input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "ans = 0", "ans", "0", "for i in range(N):\n if a[a[i]-1] == i+1:\n ans += 1\n ", "i", "range(N)", "range", "N", "if a[a[i]-1] == i+1:\n ans += 1\n ", "a[a[i]-1] == i+1", "a[a[i]-1]", "a", "a[i]-1", "a[i]", "a", "i", "1", "i+1", "i", "1", "ans += 1", "ans", "1", "print(ans//2)", "print", "ans//2", "ans", "2", "resolve()", "resolve", "def resolve():\n N = int(input())\n a = list(map(int, input().split()))\n ans = 0\n for i in range(N):\n if a[a[i]-1] == i+1:\n ans += 1\n print(ans//2)", "def resolve():\n N = int(input())\n a = list(map(int, input().split()))\n ans = 0\n for i in range(N):\n if a[a[i]-1] == i+1:\n ans += 1\n print(ans//2)", "resolve" ]

[ 7, 15, 0, 13, 4, 13, 4, 18, 4, 18, 13, 13, 13, 0, 13, 2, 39, 17, 4, 13, 4, 13, 13, 4, 18, 4, 18, 4, 18, 13, 13, 13, 13, 0, 13, 17, 28, 13, 4, 13, 17, 2, 13, 17, 14, 2, 18, 13, 18, 13, 13, 13, 0, 13, 17, 4, 13, 2, 13, 17, 10, 17, 13, 10, 17, 13, 10, 4, 13, 10, 2, 13 ]

[ [ 67, 3 ], [ 70, 14 ], [ 61, 34 ], [ 38, 37 ], [ 68, 42 ], [ 71, 47 ], [ 71, 49 ], [ 37, 50 ], [ 37, 51 ], [ 64, 53 ], [ 65, 58 ], [ 62, 58 ], [ 61, 62 ], [ 64, 65 ], [ 67, 68 ], [ 70, 71 ] ]

[ "from sys import stdin\n\nn = int(stdin.readline().rstrip())\nli = [1]+list(map(int,stdin.readline().rstrip().split()))\npoint = 0\nfor i in range(1,n+1):\n if li[li[i]] == i:\n point += 1\nprint(point//2)", "from sys import stdin", "n = int(stdin.readline().rstrip())", "n", "int(stdin.readline().rstrip())", "int", "stdin.readline().rstrip()", "stdin.readline().rstrip", "stdin.readline()", "stdin.readline", "stdin", "readline", "rstrip", "li = [1]+list(map(int,stdin.readline().rstrip().split()))", "li", "[1]+list(map(int,stdin.readline().rstrip().split()))", "[1]", "1", "list(map(int,stdin.readline().rstrip().split()))", "list", "map(int,stdin.readline().rstrip().split())", "map", "int", "stdin.readline().rstrip().split()", "stdin.readline().rstrip().split", "stdin.readline().rstrip()", "stdin.readline().rstrip", "stdin.readline()", "stdin.readline", "stdin", "readline", "rstrip", "split", "point = 0", "point", "0", "for i in range(1,n+1):\n if li[li[i]] == i:\n point += 1", "i", "range(1,n+1)", "range", "1", "n+1", "n", "1", "if li[li[i]] == i:\n point += 1", "li[li[i]] == i", "li[li[i]]", "li", "li[i]", "li", "i", "i", "point += 1", "point", "1", "print(point//2)", "print", "point//2", "point", "2", "point = 0", "0", "point", "point += 1", "1", "point", "n = int(stdin.readline().rstrip())", "int(stdin.readline().rstrip())", "n", "li = [1]+list(map(int,stdin.readline().rstrip().split()))", "[1]+list(map(int,stdin.readline().rstrip().split()))", "li" ]

[ 7, 15, 13, 0, 13, 12, 4, 18, 4, 18, 18, 13, 13, 13, 13, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 41, 28, 13, 4, 13, 2, 13, 17, 4, 17, 0, 13, 13, 28, 13, 4, 13, 17, 2, 13, 17, 0, 18, 13, 13, 18, 13, 2, 13, 17, 0, 13, 17, 28, 13, 4, 13, 17, 2, 13, 17, 14, 2, 18, 13, 18, 13, 13, 13, 0, 13, 17, 4, 13, 2, 13, 17, 10, 17, 13, 10, 12, 13, 10, 4, 13, 10, 17, 13, 10, 13, 13, 10, 4, 13 ]

[ [ 94, 4 ], [ 97, 16 ], [ 95, 20 ], [ 106, 22 ], [ 95, 31 ], [ 36, 35 ], [ 98, 39 ], [ 103, 44 ], [ 48, 47 ], [ 98, 52 ], [ 58, 55 ], [ 104, 56 ], [ 47, 57 ], [ 107, 59 ], [ 47, 61 ], [ 91, 64 ], [ 68, 67 ], [ 98, 72 ], [ 104, 77 ], [ 55, 78 ], [ 104, 79 ], [ 67, 80 ], [ 67, 81 ], [ 100, 83 ], [ 101, 88 ], [ 92, 88 ], [ 91, 92 ], [ 94, 95 ], [ 97, 98 ], [ 100, 101 ], [ 103, 104 ], [ 106, 107 ] ]

[ "import sys\ninput = lambda: sys.stdin.readline().rstrip()\nn = int(input())\na = list(map(int, input().split()))\nto = [0 for _ in range(n + 1)]\n\nfor i in range(1, n + 1):\n to[i] = a[i - 1]\nans = 0\nfor i in range(1, n + 1):\n if to[to[i]] == i:\n ans += 1\nprint(ans // 2)", "import sys", "sys", "input = lambda: sys.stdin.readline().rstrip()", "input", "lambda: sys.stdin.readline().rstrip()", "sys.stdin.readline().rstrip()", "sys.stdin.readline().rstrip", "sys.stdin.readline()", "sys.stdin.readline", "sys.stdin", "sys", "stdin", "readline", "rstrip", "n = int(input())", "n", "int(input())", "int", "input()", "input", "a = list(map(int, input().split()))", "a", "list(map(int, input().split()))", "list", "map(int, input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "0 for _ in range(n + 1)", "for _ in range(n + 1)", "_", "range(n + 1)", "range", "n + 1", "n", "1", "for _ in range(n + 1)", "0", "to = [0 for _ in range(n + 1)]", "to", "[0 for _ in range(n + 1)]", "for i in range(1, n + 1):\n to[i] = a[i - 1]", "i", "range(1, n + 1)", "range", "1", "n + 1", "n", "1", "to[i] = a[i - 1]", "to[i]", "to", "i", "a[i - 1]", "a", "i - 1", "i", "1", "ans = 0", "ans", "0", "for i in range(1, n + 1):\n if to[to[i]] == i:\n ans += 1", "i", "range(1, n + 1)", "range", "1", "n + 1", "n", "1", "if to[to[i]] == i:\n ans += 1", "to[to[i]] == i", "to[to[i]]", "to", "to[i]", "to", "i", "i", "ans += 1", "ans", "1", "print(ans // 2)", "print", "ans // 2", "ans", "2", "ans = 0", "0", "ans", "input = lambda: sys.stdin.readline().rstrip()", "lambda: sys.stdin.readline().rstrip()", "input", "n = int(input())", "int(input())", "n", "ans += 1", "1", "ans", "to = [0 for _ in range(n + 1)]", "[0 for _ in range(n + 1)]", "to", "a = list(map(int, input().split()))", "list(map(int, input().split()))", "a" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 17, 28, 13, 13, 4, 13, 13, 17, 14, 2, 13, 18, 13, 2, 13, 17, 0, 13, 17, 4, 13, 2, 13, 17, 10, 17, 13, 10, 17, 13, 10, 4, 13, 10, 4, 13 ]

[ [ 52, 2 ], [ 55, 8 ], [ 49, 20 ], [ 56, 27 ], [ 56, 33 ], [ 46, 38 ], [ 47, 43 ], [ 50, 43 ], [ 46, 47 ], [ 49, 50 ], [ 52, 53 ], [ 55, 56 ] ]

[ "n = int(input())\n\na = list(map(int,input().split()))\n\nres = 0\n\nfor i,v in enumerate(a,1):\n if i == a[v-1]:\n res += 1\nprint(res//2)", "n = int(input())", "n", "int(input())", "int", "input()", "input", "a = list(map(int,input().split()))", "a", "list(map(int,input().split()))", "list", "map(int,input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "res = 0", "res", "0", "for i,v in enumerate(a,1):\n if i == a[v-1]:\n res += 1", "i", "v", "enumerate(a,1)", "enumerate", "a", "1", "if i == a[v-1]:\n res += 1", "i == a[v-1]", "i", "a[v-1]", "a", "v-1", "v", "1", "res += 1", "res", "1", "print(res//2)", "print", "res//2", "res", "2", "res += 1", "1", "res", "res = 0", "0", "res", "n = int(input())", "int(input())", "n", "a = list(map(int,input().split()))", "list(map(int,input().split()))", "a" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 2, 39, 17, 13, 0, 13, 17, 28, 13, 13, 4, 13, 13, 14, 18, 13, 13, 9, 14, 2, 2, 18, 13, 2, 13, 17, 17, 13, 0, 13, 17, 0, 18, 13, 13, 17, 0, 18, 13, 2, 13, 17, 17, 4, 13, 13, 10, 4, 13, 10, 4, 13, 10, 17, 13, 10, 2, 13, 10, 17, 13 ]

[ [ 68, 2 ], [ 71, 8 ], [ 77, 20 ], [ 69, 24 ], [ 74, 26 ], [ 72, 33 ], [ 78, 36 ], [ 72, 43 ], [ 80, 50 ], [ 56, 53 ], [ 78, 54 ], [ 63, 58 ], [ 78, 59 ], [ 81, 66 ], [ 75, 66 ], [ 68, 69 ], [ 71, 72 ], [ 74, 75 ], [ 77, 78 ], [ 80, 81 ] ]

[ "n = int(input())\nA = list(map(int, input().split()))\nchecked = [False] * n\nans = 0\nfor i, a in enumerate(A):\n if checked[i]:\n continue\n if A[a - 1] - 1 == i:\n ans += 1\n checked[i] = True\n checked[a - 1] = True\nprint(ans)", "n = int(input())", "n", "int(input())", "int", "input()", "input", "A = list(map(int, input().split()))", "A", "list(map(int, input().split()))", "list", "map(int, input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "checked = [False] * n", "checked", "[False] * n", "[False]", "False", "n", "ans = 0", "ans", "0", "for i, a in enumerate(A):\n if checked[i]:\n continue\n if A[a - 1] - 1 == i:\n ans += 1\n checked[i] = True\n checked[a - 1] = True", "i", "a", "enumerate(A)", "enumerate", "A", "if checked[i]:\n continue\n ", "checked[i]", "checked", "i", "continue", "if A[a - 1] - 1 == i:\n ans += 1\n checked[i] = True\n checked[a - 1] = True", "A[a - 1] - 1 == i", "A[a - 1] - 1", "A[a - 1]", "A", "a - 1", "a", "1", "1", "i", "ans += 1", "ans", "1", "checked[i] = True", "checked[i]", "checked", "i", "True", "checked[a - 1] = True", "checked[a - 1]", "checked", "a - 1", "a", "1", "True", "print(ans)", "print", "ans", "n = int(input())", "int(input())", "n", "A = list(map(int, input().split()))", "list(map(int, input().split()))", "A", "ans = 0", "0", "ans", "checked = [False] * n", "[False] * n", "checked", "ans += 1", "1", "ans" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 41, 28, 13, 4, 13, 13, 4, 17, 0, 13, 13, 0, 13, 17, 28, 13, 4, 13, 13, 14, 2, 18, 13, 13, 17, 9, 14, 2, 18, 13, 2, 18, 13, 13, 17, 2, 13, 17, 0, 13, 17, 0, 18, 13, 13, 17, 0, 18, 13, 2, 18, 13, 13, 17, 17, 0, 18, 13, 13, 17, 4, 13, 13, 10, 17, 13, 10, 17, 13, 10, 4, 13, 10, 13, 13, 10, 4, 13 ]

[ [ 95, 2 ], [ 89, 8 ], [ 22, 21 ], [ 96, 24 ], [ 92, 28 ], [ 83, 31 ], [ 35, 34 ], [ 96, 37 ], [ 75, 40 ], [ 61, 40 ], [ 93, 41 ], [ 34, 42 ], [ 90, 48 ], [ 90, 51 ], [ 34, 52 ], [ 34, 55 ], [ 86, 58 ], [ 64, 61 ], [ 93, 62 ], [ 34, 63 ], [ 73, 66 ], [ 93, 67 ], [ 90, 70 ], [ 34, 71 ], [ 78, 75 ], [ 93, 76 ], [ 34, 77 ], [ 87, 81 ], [ 84, 81 ], [ 83, 84 ], [ 86, 87 ], [ 89, 90 ], [ 92, 93 ], [ 95, 96 ] ]

[ "N=int(input())\na=list(map(int,input().split()))\n\nchk=[0 for i in range(N)]\nans=0\nfor i in range(N):\n if chk[i]==1:\n continue\n if a[a[i]-1]==(i+1):\n ans+=1\n chk[i]=1\n chk[a[i]-1]=1\n else:\n chk[i]=1\n\nprint(ans)", "N=int(input())", "N", "int(input())", "int", "input()", "input", "a=list(map(int,input().split()))", "a", "list(map(int,input().split()))", "list", "map(int,input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "0 for i in range(N)", "for i in range(N)", "i", "range(N)", "range", "N", "for i in range(N)", "0", "chk=[0 for i in range(N)]", "chk", "[0 for i in range(N)]", "ans=0", "ans", "0", "for i in range(N):\n if chk[i]==1:\n continue\n if a[a[i]-1]==(i+1):\n ans+=1\n chk[i]=1\n chk[a[i]-1]=1\n else:\n chk[i]=1", "i", "range(N)", "range", "N", "if chk[i]==1:\n continue\n ", "chk[i]==1", "chk[i]", "chk", "i", "1", "continue", "if a[a[i]-1]==(i+1):\n ans+=1\n chk[i]=1\n chk[a[i]-1]=1\n else:\n chk[i]=1", "a[a[i]-1]==(i+1)", "a[a[i]-1]", "a", "a[i]-1", "a[i]", "a", "i", "1", "i+1", "i", "1", "ans+=1", "ans", "1", "chk[i]=1", "chk[i]", "chk", "i", "1", "chk[a[i]-1]=1", "chk[a[i]-1]", "chk", "a[i]-1", "a[i]", "a", "i", "1", "1", "chk[i]=1", "chk[i]", "chk", "i", "1", "print(ans)", "print", "ans", "ans=0", "0", "ans", "ans+=1", "1", "ans", "a=list(map(int,input().split()))", "list(map(int,input().split()))", "a", "chk=[0 for i in range(N)]", "[0 for i in range(N)]", "chk", "N=int(input())", "int(input())", "N" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 17, 0, 31, 13, 4, 13, 13, 4, 18, 4, 13, 13, 28, 13, 13, 4, 13, 13, 14, 2, 18, 13, 2, 18, 13, 13, 17, 2, 13, 17, 0, 13, 17, 4, 13, 2, 13, 17, 10, 4, 13, 10, 17, 13, 10, 17, 13 ]

[ [ 48, 2 ], [ 54, 8 ], [ 13, 11 ], [ 51, 40 ], [ 52, 45 ], [ 55, 45 ], [ 48, 49 ], [ 51, 52 ], [ 54, 55 ] ]

[ "p = int(input())\nans = 0\n*A,= map(int,input().split())\nfor j,i in enumerate(A):\n if A[A[j]-1]==j+1:\n ans+=1\nprint(ans//2)", "p = int(input())", "p", "int(input())", "int", "input()", "input", "ans = 0", "ans", "0", "*A,= map(int,input().split())", "*A", "A", "map(int,input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "for j,i in enumerate(A):\n if A[A[j]-1]==j+1:\n ans+=1", "j", "i", "enumerate(A)", "enumerate", "A", "if A[A[j]-1]==j+1:\n ans+=1", "A[A[j]-1]==j+1", "A[A[j]-1]", "A", "A[j]-1", "A[j]", "A", "j", "1", "j+1", "j", "1", "ans+=1", "ans", "1", "print(ans//2)", "print", "ans//2", "ans", "2", "p = int(input())", "int(input())", "p", "ans+=1", "1", "ans", "ans = 0", "0", "ans" ]

[ 7, 12, 13, 0, 13, 4, 13, 4, 13, 41, 28, 13, 4, 18, 4, 13, 13, 4, 4, 13, 13, 0, 13, 13, 0, 13, 17, 28, 13, 13, 4, 13, 13, 14, 2, 18, 13, 2, 13, 17, 2, 13, 17, 0, 13, 17, 4, 13, 2, 13, 17, 4, 13, 10, 12, 13 ]

[ [ 5, 4 ], [ 12, 11 ], [ 11, 20 ], [ 23, 22 ], [ 26, 25 ], [ 22, 32 ], [ 22, 36 ], [ 45, 44 ], [ 44, 49 ], [ 25, 49 ], [ 55, 52 ] ]

[ "def main():\n N=int(input())\n a=[int(_) for _ in input().split()]\n ans = 0\n for i,v in enumerate(a):\n if a[v-1] == i+1:\n ans += 1\n print(ans//2)\n\nmain()", "def main():\n N=int(input())\n a=[int(_) for _ in input().split()]\n ans = 0\n for i,v in enumerate(a):\n if a[v-1] == i+1:\n ans += 1\n print(ans//2)", "main", "N=int(input())", "N", "int(input())", "int", "input()", "input", "int(_) for _ in input().split()", "for _ in input().split()", "_", "input().split()", "().split", "()", "input", "split", "for _ in input().split()", "int(_)", "int", "_", "a=[int(_) for _ in input().split()]", "a", "[int(_) for _ in input().split()]", "ans = 0", "ans", "0", "for i,v in enumerate(a):\n if a[v-1] == i+1:\n ans += 1\n ", "i", "v", "enumerate(a)", "enumerate", "a", "if a[v-1] == i+1:\n ans += 1\n ", "a[v-1] == i+1", "a[v-1]", "a", "v-1", "v", "1", "i+1", "i", "1", "ans += 1", "ans", "1", "print(ans//2)", "print", "ans//2", "ans", "2", "main()", "main", "def main():\n N=int(input())\n a=[int(_) for _ in input().split()]\n ans = 0\n for i,v in enumerate(a):\n if a[v-1] == i+1:\n ans += 1\n print(ans//2)", "def main():\n N=int(input())\n a=[int(_) for _ in input().split()]\n ans = 0\n for i,v in enumerate(a):\n if a[v-1] == i+1:\n ans += 1\n print(ans//2)", "main" ]

[ 7, 15, 13, 15, 13, 0, 13, 12, 2, 4, 13, 13, 17, 23, 0, 13, 18, 18, 18, 13, 13, 13, 13, 0, 13, 18, 18, 18, 13, 13, 13, 13, 0, 13, 18, 18, 18, 13, 13, 13, 13, 4, 18, 13, 13, 17, 0, 13, 4, 13, 13, 4, 18, 4, 13, 13, 31, 13, 0, 13, 17, 28, 13, 13, 4, 13, 13, 14, 2, 18, 13, 13, 13, 0, 13, 17, 4, 13, 2, 13, 17, 10, 12, 13, 10, 18, 13, 10, 18, 13, 10, 17, 13, 10, 4, 13, 10, 18, 13, 10, 17, 13 ]

[ [ 82, 6 ], [ 85, 15 ], [ 97, 24 ], [ 88, 33 ], [ 94, 47 ], [ 83, 50 ], [ 86, 54 ], [ 94, 56 ], [ 91, 59 ], [ 100, 74 ], [ 101, 79 ], [ 92, 79 ], [ 82, 83 ], [ 85, 86 ], [ 88, 89 ], [ 91, 92 ], [ 94, 95 ], [ 97, 98 ], [ 100, 101 ] ]

[ "#! /usr/bin/env python3\n\nimport sys\nimport numpy as np\nint1 = lambda x: int(x) - 1\nread = sys.stdin.buffer.read\nreadline = sys.stdin.buffer.readline\nreadlines = sys.stdin.buffer.readlines\nsys.setrecursionlimit(500000)\n\n_, *A = map(int1, read().split())\n\nans = 0\nfor i, a in enumerate(A):\n if A[a] == i:\n ans += 1\n\nprint(ans // 2)", "import sys", "sys", "import numpy as np", "numpy", "int1 = lambda x: int(x) - 1", "int1", "lambda x: int(x) - 1", "int(x) - 1", "int(x)", "int", "x", "1", "x", "read = sys.stdin.buffer.read", "read", "sys.stdin.buffer.read", "sys.stdin.buffer", "sys.stdin", "sys", "stdin", "buffer", "read", "readline = sys.stdin.buffer.readline", "readline", "sys.stdin.buffer.readline", "sys.stdin.buffer", "sys.stdin", "sys", "stdin", "buffer", "readline", "readlines = sys.stdin.buffer.readlines", "readlines", "sys.stdin.buffer.readlines", "sys.stdin.buffer", "sys.stdin", "sys", "stdin", "buffer", "readlines", "sys.setrecursionlimit(500000)", "sys.setrecursionlimit", "sys", "setrecursionlimit", "500000", "_, *A = map(int1, read().split())", "_", "map(int1, read().split())", "map", "int1", "read().split()", "().split", "()", "read", "split", "*A", "A", "ans = 0", "ans", "0", "for i, a in enumerate(A):\n if A[a] == i:\n ans += 1", "i", "a", "enumerate(A)", "enumerate", "A", "if A[a] == i:\n ans += 1", "A[a] == i", "A[a]", "A", "a", "i", "ans += 1", "ans", "1", "print(ans // 2)", "print", "ans // 2", "ans", "2", "int1 = lambda x: int(x) - 1", "lambda x: int(x) - 1", "int1", "read = sys.stdin.buffer.read", "sys.stdin.buffer.read", "read", "readlines = sys.stdin.buffer.readlines", "sys.stdin.buffer.readlines", "readlines", "ans = 0", "0", "ans", "_, *A = map(int1, read().split())", "map(int1, read().split())", "_", "readline = sys.stdin.buffer.readline", "sys.stdin.buffer.readline", "readline", "ans += 1", "1", "ans" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 17, 28, 13, 4, 13, 13, 14, 2, 2, 18, 13, 2, 18, 13, 13, 17, 17, 13, 0, 13, 17, 4, 13, 2, 13, 17, 10, 17, 13, 10, 17, 13, 10, 4, 13, 10, 4, 13 ]

[ [ 54, 2 ], [ 57, 8 ], [ 51, 20 ], [ 24, 23 ], [ 55, 26 ], [ 58, 31 ], [ 58, 34 ], [ 23, 35 ], [ 23, 38 ], [ 48, 40 ], [ 49, 45 ], [ 52, 45 ], [ 48, 49 ], [ 51, 52 ], [ 54, 55 ], [ 57, 58 ] ]

[ "n = int(input())\na = list(map(int,input().split()))\nans = 0\nfor i in range(n):\n if a[a[i]-1]-1 == i:\n ans += 1\nprint(ans // 2)", "n = int(input())", "n", "int(input())", "int", "input()", "input", "a = list(map(int,input().split()))", "a", "list(map(int,input().split()))", "list", "map(int,input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "ans = 0", "ans", "0", "for i in range(n):\n if a[a[i]-1]-1 == i:\n ans += 1", "i", "range(n)", "range", "n", "if a[a[i]-1]-1 == i:\n ans += 1", "a[a[i]-1]-1 == i", "a[a[i]-1]-1", "a[a[i]-1]", "a", "a[i]-1", "a[i]", "a", "i", "1", "1", "i", "ans += 1", "ans", "1", "print(ans // 2)", "print", "ans // 2", "ans", "2", "ans += 1", "1", "ans", "ans = 0", "0", "ans", "n = int(input())", "int(input())", "n", "a = list(map(int,input().split()))", "list(map(int,input().split()))", "a" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 17, 28, 13, 4, 13, 13, 0, 13, 18, 13, 13, 14, 2, 18, 13, 2, 13, 17, 2, 13, 17, 0, 13, 17, 4, 13, 2, 13, 17, 10, 18, 13, 10, 17, 13, 10, 4, 13, 10, 4, 13, 10, 17, 13 ]

[ [ 60, 2 ], [ 57, 8 ], [ 54, 20 ], [ 24, 23 ], [ 61, 26 ], [ 51, 28 ], [ 58, 30 ], [ 23, 31 ], [ 58, 35 ], [ 52, 37 ], [ 23, 40 ], [ 63, 43 ], [ 64, 48 ], [ 55, 48 ], [ 51, 52 ], [ 54, 55 ], [ 57, 58 ], [ 60, 61 ], [ 63, 64 ] ]

[ "N=int(input())\nlike=list(map(int,input().split()))\ncount=0\n\nfor i in range(N):\n like_1=like[i]\n #print(\"like_1\")\n #print(like_1)\n if like[like_1-1]==i+1:\n #print(like[like_1-1])\n #print(i+1)\n count+=1\n #print(\"///\")\n \nprint(count//2)", "N=int(input())", "N", "int(input())", "int", "input()", "input", "like=list(map(int,input().split()))", "like", "list(map(int,input().split()))", "list", "map(int,input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "count=0", "count", "0", "for i in range(N):\n like_1=like[i]\n #print(\"like_1\")\n #print(like_1)\n if like[like_1-1]==i+1:\n #print(like[like_1-1])\n #print(i+1)\n count+=1\n #print(\"///\")\n ", "i", "range(N)", "range", "N", "like_1=like[i]", "like_1", "like[i]", "like", "i", "if like[like_1-1]==i+1:\n #print(like[like_1-1])\n #print(i+1)\n count+=1\n #print(\"///\")\n ", "like[like_1-1]==i+1", "like[like_1-1]", "like", "like_1-1", "like_1", "1", "i+1", "i", "1", "count+=1", "count", "1", "print(count//2)", "print", "count//2", "count", "2", "like_1=like[i]", "like[i]", "like_1", "count=0", "0", "count", "like=list(map(int,input().split()))", "list(map(int,input().split()))", "like", "N=int(input())", "int(input())", "N", "count+=1", "1", "count" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 39, 0, 13, 17, 28, 13, 4, 13, 17, 13, 4, 18, 13, 13, 39, 2, 13, 17, 18, 13, 13, 28, 13, 13, 13, 14, 2, 18, 18, 13, 2, 13, 17, 17, 13, 0, 13, 17, 4, 13, 2, 13, 17, 10, 17, 13, 10, 4, 13, 10, 39, 13, 10, 4, 13, 10, 17, 13 ]

[ [ 74, 2 ], [ 68, 8 ], [ 71, 20 ], [ 65, 23 ], [ 27, 26 ], [ 75, 30 ], [ 72, 33 ], [ 26, 37 ], [ 69, 40 ], [ 26, 41 ], [ 72, 50 ], [ 77, 57 ], [ 78, 62 ], [ 66, 62 ], [ 65, 66 ], [ 68, 69 ], [ 71, 72 ], [ 74, 75 ], [ 77, 78 ] ]

[ "N = int(input())\na = list(map(int, input().split()))\nlike = []\ncnt = 0\n\nfor i in range(0, N):\n like.append([i+1, a[i]])\n\nfor j, k in like:\n if like[k-1][1] == j:\n cnt += 1\n\nprint(cnt // 2)", "N = int(input())", "N", "int(input())", "int", "input()", "input", "a = list(map(int, input().split()))", "a", "list(map(int, input().split()))", "list", "map(int, input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "like = []", "like", "[]", "cnt = 0", "cnt", "0", "for i in range(0, N):\n like.append([i+1, a[i]])", "i", "range(0, N)", "range", "0", "N", "like.append([i+1, a[i]])", "like.append", "like", "append", "[i+1, a[i]]", "i+1", "i", "1", "a[i]", "a", "i", "for j, k in like:\n if like[k-1][1] == j:\n cnt += 1", "j", "k", "like", "if like[k-1][1] == j:\n cnt += 1", "like[k-1][1] == j", "like[k-1][1]", "[k-1]", "like", "k-1", "k", "1", "1", "j", "cnt += 1", "cnt", "1", "print(cnt // 2)", "print", "cnt // 2", "cnt", "2", "cnt = 0", "0", "cnt", "a = list(map(int, input().split()))", "list(map(int, input().split()))", "a", "like = []", "[]", "like", "N = int(input())", "int(input())", "N", "cnt += 1", "1", "cnt" ]

[ 7, 0, 13, 4, 13, 4, 13, 41, 28, 13, 4, 18, 4, 13, 13, 4, 4, 13, 13, 0, 13, 13, 0, 13, 17, 28, 13, 13, 4, 13, 13, 14, 2, 18, 13, 2, 13, 17, 2, 13, 17, 4, 13, 4, 13, 2, 13, 17, 10, 17, 13, 10, 13, 13, 10, 4, 13 ]

[ [ 55, 2 ], [ 10, 9 ], [ 9, 18 ], [ 52, 20 ], [ 49, 23 ], [ 53, 30 ], [ 53, 34 ], [ 50, 46 ], [ 49, 50 ], [ 52, 53 ], [ 55, 56 ] ]

[ "n = int(input())\na = [int(x) for x in input().split()]\nans = 0\nfor i, a_i in enumerate(a):\n if a[a_i - 1] == i + 1: ans += 1\nprint(int(ans/2))", "n = int(input())", "n", "int(input())", "int", "input()", "input", "int(x) for x in input().split()", "for x in input().split()", "x", "input().split()", "().split", "()", "input", "split", "for x in input().split()", "int(x)", "int", "x", "a = [int(x) for x in input().split()]", "a", "[int(x) for x in input().split()]", "ans = 0", "ans", "0", "for i, a_i in enumerate(a):\n if a[a_i - 1] == i + 1: ans += 1", "i", "a_i", "enumerate(a)", "enumerate", "a", "if a[a_i - 1] == i + 1: ans ", "a[a_i - 1] == i + 1", "a[a_i - 1]", "a", "a_i - 1", "a_i", "1", "i + 1", "i", "1", "print(int(ans/2))", "print", "int(ans/2)", "int", "ans/2", "ans", "2", "ans = 0", "0", "ans", "a = [int(x) for x in input().split()]", "[int(x) for x in input().split()]", "a", "n = int(input())", "int(input())", "n" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 41, 28, 13, 13, 4, 13, 13, 4, 2, 13, 17, 13, 0, 13, 13, 0, 13, 17, 28, 13, 13, 4, 18, 13, 13, 14, 2, 13, 18, 13, 13, 0, 13, 17, 4, 13, 2, 13, 17, 10, 17, 13, 10, 4, 13, 10, 13, 13, 10, 4, 13, 10, 17, 13 ]

[ [ 68, 2 ], [ 62, 8 ], [ 63, 25 ], [ 65, 32 ], [ 59, 35 ], [ 66, 42 ], [ 63, 42 ], [ 66, 48 ], [ 63, 48 ], [ 71, 51 ], [ 72, 56 ], [ 60, 56 ], [ 59, 60 ], [ 62, 63 ], [ 65, 66 ], [ 68, 69 ], [ 71, 72 ] ]

[ "n = int(input()) #兎の数\na = list(map(int,(input().split())))\na = {i+1: v for i, v in enumerate(a)}\n#print(a)\n#print(a[1])\n\ncounter = 0\n\nfor i,j in a.items():\n if i == a[j]:\n #print(i,j)\n counter += 1\n\nprint(counter//2)", "n = int(input())", "n", "int(input())", "int", "input()", "input", "a = list(map(int,(input().split())))", "a", "list(map(int,(input().split())))", "list", "map(int,(input().split()))", "map", "int", "input().split()", "().split", "()", "input", "split", "i+1: v for i, v in enumerate(a)", "for i, v in enumerate(a)", "i", "v", "enumerate(a)", "enumerate", "a", "for i, v in enumerate(a)", "i+1", "i", "1", "v", "a = {i+1: v for i, v in enumerate(a)}", "a", "{i+1: v for i, v in enumerate(a)}", "counter = 0", "counter", "0", "for i,j in a.items():\n if i == a[j]:\n #print(i,j)\n counter += 1", "i", "j", "a.items()", "a.items", "a", "items", "if i == a[j]:\n #print(i,j)\n counter += 1", "i == a[j]", "i", "a[j]", "a", "j", "counter += 1", "counter", "1", "print(counter//2)", "print", "counter//2", "counter", "2", "counter = 0", "0", "counter", "a = list(map(int,(input().split())))", "list(map(int,(input().split())))", "a", "a = {i+1: v for i, v in enumerate(a)}", "{i+1: v for i, v in enumerate(a)}", "a", "n = int(input())", "int(input())", "n", "counter += 1", "1", "counter" ]

[ 7, 15, 12, 13, 0, 13, 18, 13, 13, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 12, 2, 4, 13, 13, 17, 23, 4, 18, 4, 13, 13, 0, 13, 2, 39, 17, 13, 0, 13, 17, 28, 13, 4, 13, 13, 0, 13, 18, 13, 13, 14, 2, 2, 18, 13, 13, 17, 2, 18, 13, 13, 13, 0, 18, 13, 13, 17, 0, 18, 13, 13, 17, 0, 13, 17, 4, 13, 13, 14, 2, 13, 17, 4, 13, 10, 12, 13 ]

[ [ 6, 5 ], [ 11, 10 ], [ 5, 14 ], [ 17, 16 ], [ 5, 31 ], [ 35, 34 ], [ 10, 38 ], [ 41, 40 ], [ 44, 43 ], [ 10, 46 ], [ 49, 48 ], [ 16, 50 ], [ 43, 51 ], [ 70, 55 ], [ 34, 56 ], [ 48, 57 ], [ 16, 61 ], [ 48, 62 ], [ 43, 63 ], [ 68, 65 ], [ 34, 66 ], [ 43, 67 ], [ 73, 70 ], [ 34, 71 ], [ 48, 72 ], [ 76, 75 ], [ 75, 79 ], [ 40, 79 ], [ 88, 85 ] ]

[ "from sys import stdin\ndef main():\n #入力\n readline=stdin.readline\n N=int(readline())\n a=list(map(lambda x:int(x)-1,readline().split()))\n\n flags=[False]*N\n res=0\n for i in range(N):\n j=a[i]\n if flags[j]==False and a[j]==i:\n flags[i]=True\n flags[j]=True\n res+=1\n\n print(res)\n \nif __name__==\"__main__\":\n main()", "from sys import stdin", "def main():\n #入力\n readline=stdin.readline\n N=int(readline())\n a=list(map(lambda x:int(x)-1,readline().split()))\n\n flags=[False]*N\n res=0\n for i in range(N):\n j=a[i]\n if flags[j]==False and a[j]==i:\n flags[i]=True\n flags[j]=True\n res+=1\n\n print(res)\n ", "main", "readline=stdin.readline", "readline", "stdin.readline", "stdin", "readline", "N=int(readline())", "N", "int(readline())", "int", "readline()", "readline", "a=list(map(lambda x:int(x)-1,readline().split()))", "a", "list(map(lambda x:int(x)-1,readline().split()))", "list", "map(lambda x:int(x)-1,readline().split())", "map", "lambda x:int(x)-1", "int(x)-1", "int(x)", "int", "x", "1", "x", "readline().split()", "().split", "()", "readline", "split", "flags=[False]*N", "flags", "[False]*N", "[False]", "False", "N", "res=0", "res", "0", "for i in range(N):\n j=a[i]\n if flags[j]==False and a[j]==i:\n flags[i]=True\n flags[j]=True\n res+=1\n\n ", "i", "range(N)", "range", "N", "j=a[i]", "j", "a[i]", "a", "i", "if flags[j]==False and a[j]==i:\n flags[i]=True\n flags[j]=True\n res+=1\n\n ", "flags[j]==False and a[j]==i", "flags[j]==False", "flags[j]", "flags", "j", "False", "a[j]==i", "a[j]", "a", "j", "i", "flags[i]=True", "flags[i]", "flags", "i", "True", "flags[j]=True", "flags[j]", "flags", "j", "True", "res+=1", "res", "1", "print(res)", "print", "res", "if __name__==\"__main__\":\n main()", "__name__==\"__main__\"", "__name__", "\"__main__\"", "main()", "main", "def main():\n #入力\n readline=stdin.readline\n N=int(readline())\n a=list(map(lambda x:int(x)-1,readline().split()))\n\n flags=[False]*N\n res=0\n for i in range(N):\n j=a[i]\n if flags[j]==False and a[j]==i:\n flags[i]=True\n flags[j]=True\n res+=1\n\n print(res)\n ", "def main():\n #入力\n readline=stdin.readline\n N=int(readline())\n a=list(map(lambda x:int(x)-1,readline().split()))\n\n flags=[False]*N\n res=0\n for i in range(N):\n j=a[i]\n if flags[j]==False and a[j]==i:\n flags[i]=True\n flags[j]=True\n res+=1\n\n print(res)\n ", "main" ]

[ 7, 15, 13, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 17, 0, 13, 17, 28, 13, 4, 13, 13, 0, 18, 13, 2, 13, 17, 18, 13, 13, 28, 13, 4, 13, 13, 14, 2, 18, 13, 18, 13, 2, 13, 17, 2, 13, 17, 0, 13, 17, 0, 13, 17, 4, 13, 13, 10, 4, 13, 10, 4, 13, 10, 17, 13, 10, 17, 13, 10, 17, 13, 10, 17, 13 ]

[ [ 71, 4 ], [ 68, 10 ], [ 74, 22 ], [ 80, 25 ], [ 29, 28 ], [ 72, 31 ], [ 38, 33 ], [ 75, 34 ], [ 28, 36 ], [ 69, 39 ], [ 28, 40 ], [ 43, 42 ], [ 72, 45 ], [ 75, 49 ], [ 75, 51 ], [ 42, 53 ], [ 42, 56 ], [ 83, 59 ], [ 77, 62 ], [ 78, 66 ], [ 84, 66 ], [ 81, 66 ], [ 68, 69 ], [ 71, 72 ], [ 74, 75 ], [ 77, 78 ], [ 80, 81 ], [ 83, 84 ] ]

[ "import collections\nn = int(input())\na = list(map(int, input().split()))\nd = {}\nans = 0\nfor i in range(n):\n d[i + 1] = a[i]\nfor i in range(n):\n if d[d[i + 1]] == i + 1:\n ans += 1\nans //= 2\nprint(ans)", "import collections", "collections", "n = int(input())", "n", "int(input())", "int", "input()", "input", "a = list(map(int, input().split()))", "a", "list(map(int, input().split()))", "list", "map(int, input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "d = {}", "d", "{}", "ans = 0", "ans", "0", "for i in range(n):\n d[i + 1] = a[i]", "i", "range(n)", "range", "n", "d[i + 1] = a[i]", "d[i + 1]", "d", "i + 1", "i", "1", "a[i]", "a", "i", "for i in range(n):\n if d[d[i + 1]] == i + 1:\n ans += 1", "i", "range(n)", "range", "n", "if d[d[i + 1]] == i + 1:\n ans += 1", "d[d[i + 1]] == i + 1", "d[d[i + 1]]", "d", "d[i + 1]", "d", "i + 1", "i", "1", "i + 1", "i", "1", "ans += 1", "ans", "1", "ans //= 2", "ans", "2", "print(ans)", "print", "ans", "a = list(map(int, input().split()))", "list(map(int, input().split()))", "a", "n = int(input())", "int(input())", "n", "d = {}", "{}", "d", "ans //= 2", "2", "ans", "ans = 0", "0", "ans", "ans += 1", "1", "ans" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 17, 28, 13, 4, 13, 13, 0, 13, 2, 18, 13, 13, 17, 14, 2, 18, 13, 13, 2, 13, 17, 0, 13, 17, 4, 13, 4, 13, 13, 10, 4, 13, 10, 17, 13, 10, 4, 13, 10, 17, 13, 10, 2, 13 ]

[ [ 51, 2 ], [ 57, 8 ], [ 54, 20 ], [ 24, 23 ], [ 52, 26 ], [ 63, 28 ], [ 58, 31 ], [ 23, 32 ], [ 58, 37 ], [ 64, 38 ], [ 23, 40 ], [ 60, 43 ], [ 61, 49 ], [ 55, 49 ], [ 51, 52 ], [ 54, 55 ], [ 57, 58 ], [ 60, 61 ], [ 63, 64 ] ]

[ "N = int(input())\na = list(map(int, input().split()))\n\nans = 0\nfor i in range(N):\n ai = a[i]-1\n if a[ai]==i+1:\n ans += 0.5\n\nprint(int(ans))", "N = int(input())", "N", "int(input())", "int", "input()", "input", "a = list(map(int, input().split()))", "a", "list(map(int, input().split()))", "list", "map(int, input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "ans = 0", "ans", "0", "for i in range(N):\n ai = a[i]-1\n if a[ai]==i+1:\n ans += 0.5", "i", "range(N)", "range", "N", "ai = a[i]-1", "ai", "a[i]-1", "a[i]", "a", "i", "1", "if a[ai]==i+1:\n ans += 0.5", "a[ai]==i+1", "a[ai]", "a", "ai", "i+1", "i", "1", "ans += 0.5", "ans", "0.5", "print(int(ans))", "print", "int(ans)", "int", "ans", "N = int(input())", "int(input())", "N", "ans = 0", "0", "ans", "a = list(map(int, input().split()))", "list(map(int, input().split()))", "a", "ans += 0.5", "0.5", "ans", "ai = a[i]-1", "a[i]-1", "ai" ]

[ 7, 15, 0, 13, 4, 13, 4, 13, 0, 31, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 4, 13, 13, 0, 13, 17, 28, 13, 4, 13, 13, 14, 2, 18, 13, 13, 18, 13, 2, 13, 17, 0, 13, 17, 4, 18, 18, 13, 18, 13, 13, 13, 2, 13, 17, 4, 13, 13, 10, 4, 13, 10, 4, 13, 10, 17, 13, 10, 17, 13 ]

[ [ 60, 3 ], [ 11, 9 ], [ 63, 20 ], [ 66, 25 ], [ 29, 28 ], [ 61, 31 ], [ 28, 36 ], [ 64, 38 ], [ 28, 40 ], [ 69, 43 ], [ 64, 48 ], [ 28, 51 ], [ 28, 54 ], [ 70, 58 ], [ 67, 58 ], [ 60, 61 ], [ 63, 64 ], [ 66, 67 ], [ 69, 70 ] ]

[ "from collections import defaultdict\n\nN=int(input())\n*A,=map(int,input().split())\n\nlike=defaultdict(set)\nans=0\nfor i in range(N):\n if A[i] in like[i+1]:\n ans += 1\n like[A[i]].add(i+1)\n \nprint(ans)", "from collections import defaultdict", "N=int(input())", "N", "int(input())", "int", "input()", "input", "*A,=map(int,input().split())", "*A", "A", "map(int,input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "like=defaultdict(set)", "like", "defaultdict(set)", "defaultdict", "set", "ans=0", "ans", "0", "for i in range(N):\n if A[i] in like[i+1]:\n ans += 1\n like[A[i]].add(i+1)\n ", "i", "range(N)", "range", "N", "if A[i] in like[i+1]:\n ans += 1\n ", "A[i] in like[i+1]", "A[i]", "A", "i", "like[i+1]", "like", "i+1", "i", "1", "ans += 1", "ans", "1", "like[A[i]].add(i+1)", "[A[i]].add", "[A[i]]", "like", "A[i]", "A", "i", "add", "i+1", "i", "1", "print(ans)", "print", "ans", "N=int(input())", "int(input())", "N", "like=defaultdict(set)", "defaultdict(set)", "like", "ans=0", "0", "ans", "ans += 1", "1", "ans" ]

[ 7, 0, 13, 4, 13, 4, 13, 41, 28, 13, 4, 18, 4, 13, 13, 4, 4, 13, 13, 0, 13, 13, 0, 13, 17, 28, 13, 4, 13, 13, 14, 2, 18, 13, 2, 18, 13, 13, 17, 2, 13, 17, 0, 13, 17, 4, 13, 2, 13, 17, 10, 4, 13, 10, 17, 13, 10, 13, 13, 10, 17, 13 ]

[ [ 51, 2 ], [ 10, 9 ], [ 9, 18 ], [ 57, 20 ], [ 60, 23 ], [ 27, 26 ], [ 52, 29 ], [ 58, 33 ], [ 58, 36 ], [ 26, 37 ], [ 26, 40 ], [ 54, 43 ], [ 55, 48 ], [ 61, 48 ], [ 51, 52 ], [ 54, 55 ], [ 57, 58 ], [ 60, 61 ] ]

[ "n = int(input())\na = [int(s) for s in input().split()]\n\nans = 0\nfor i in range(n):\n if a[a[i]-1] == i + 1:\n ans += 1\nprint(ans // 2)", "n = int(input())", "n", "int(input())", "int", "input()", "input", "int(s) for s in input().split()", "for s in input().split()", "s", "input().split()", "().split", "()", "input", "split", "for s in input().split()", "int(s)", "int", "s", "a = [int(s) for s in input().split()]", "a", "[int(s) for s in input().split()]", "ans = 0", "ans", "0", "for i in range(n):\n if a[a[i]-1] == i + 1:\n ans += 1", "i", "range(n)", "range", "n", "if a[a[i]-1] == i + 1:\n ans += 1", "a[a[i]-1] == i + 1", "a[a[i]-1]", "a", "a[i]-1", "a[i]", "a", "i", "1", "i + 1", "i", "1", "ans += 1", "ans", "1", "print(ans // 2)", "print", "ans // 2", "ans", "2", "n = int(input())", "int(input())", "n", "ans += 1", "1", "ans", "a = [int(s) for s in input().split()]", "[int(s) for s in input().split()]", "a", "ans = 0", "0", "ans" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 17, 28, 13, 4, 13, 13, 14, 2, 18, 13, 2, 18, 13, 13, 17, 2, 13, 17, 0, 13, 17, 4, 13, 2, 13, 17, 10, 4, 13, 10, 4, 13, 10, 17, 13, 10, 17, 13 ]

[ [ 48, 2 ], [ 51, 8 ], [ 57, 20 ], [ 24, 23 ], [ 49, 26 ], [ 52, 30 ], [ 52, 33 ], [ 23, 34 ], [ 23, 37 ], [ 54, 40 ], [ 55, 45 ], [ 58, 45 ], [ 48, 49 ], [ 51, 52 ], [ 54, 55 ], [ 57, 58 ] ]

[ "N = int(input())\na = list(map(int,input().split()))\nans = 0\nfor k in range(N):\n if a[a[k]-1] == k+1:\n ans += 1\nprint(ans//2)", "N = int(input())", "N", "int(input())", "int", "input()", "input", "a = list(map(int,input().split()))", "a", "list(map(int,input().split()))", "list", "map(int,input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "ans = 0", "ans", "0", "for k in range(N):\n if a[a[k]-1] == k+1:\n ans += 1", "k", "range(N)", "range", "N", "if a[a[k]-1] == k+1:\n ans += 1", "a[a[k]-1] == k+1", "a[a[k]-1]", "a", "a[k]-1", "a[k]", "a", "k", "1", "k+1", "k", "1", "ans += 1", "ans", "1", "print(ans//2)", "print", "ans//2", "ans", "2", "N = int(input())", "int(input())", "N", "a = list(map(int,input().split()))", "list(map(int,input().split()))", "a", "ans += 1", "1", "ans", "ans = 0", "0", "ans" ]

[ 7, 15, 13, 0, 13, 18, 13, 13, 0, 13, 12, 4, 13, 4, 13, 0, 13, 12, 4, 13, 4, 13, 13, 4, 18, 4, 18, 13, 13, 13, 0, 13, 12, 4, 18, 4, 18, 13, 13, 13, 0, 13, 4, 13, 0, 13, 4, 13, 0, 13, 17, 28, 13, 4, 13, 13, 14, 2, 2, 18, 13, 2, 18, 13, 13, 17, 17, 13, 0, 13, 17, 4, 13, 2, 13, 17, 10, 12, 13, 10, 12, 13, 10, 17, 13, 10, 18, 13, 10, 12, 13, 10, 17, 13, 10, 4, 13, 10, 4, 13 ]

[ [ 86, 4 ], [ 89, 9 ], [ 77, 16 ], [ 87, 27 ], [ 80, 31 ], [ 87, 37 ], [ 95, 41 ], [ 90, 43 ], [ 98, 45 ], [ 78, 47 ], [ 83, 49 ], [ 53, 52 ], [ 96, 55 ], [ 99, 60 ], [ 99, 63 ], [ 52, 64 ], [ 52, 67 ], [ 92, 69 ], [ 93, 74 ], [ 84, 74 ], [ 77, 78 ], [ 80, 81 ], [ 83, 84 ], [ 86, 87 ], [ 89, 90 ], [ 92, 93 ], [ 95, 96 ], [ 98, 99 ] ]

[ "import sys\n\nstdin = sys.stdin\n \nri = lambda: int(rs())\nrl = lambda: list(map(int, stdin.readline().split()))\nrs = lambda: stdin.readline().rstrip() # ignore trailing spaces\n\nN = ri()\nA = rl()\nanswer = 0\nfor i in range(N):\n if A[A[i]-1]-1 == i:\n answer += 1\n\nprint(answer//2)", "import sys", "sys", "stdin = sys.stdin", "stdin", "sys.stdin", "sys", "stdin", "ri = lambda: int(rs())", "ri", "lambda: int(rs())", "int(rs())", "int", "rs()", "rs", "rl = lambda: list(map(int, stdin.readline().split()))", "rl", "lambda: list(map(int, stdin.readline().split()))", "list(map(int, stdin.readline().split()))", "list", "map(int, stdin.readline().split())", "map", "int", "stdin.readline().split()", "stdin.readline().split", "stdin.readline()", "stdin.readline", "stdin", "readline", "split", "rs = lambda: stdin.readline().rstrip()", "rs", "lambda: stdin.readline().rstrip()", "stdin.readline().rstrip()", "stdin.readline().rstrip", "stdin.readline()", "stdin.readline", "stdin", "readline", "rstrip", "N = ri()", "N", "ri()", "ri", "A = rl()", "A", "rl()", "rl", "answer = 0", "answer", "0", "for i in range(N):\n if A[A[i]-1]-1 == i:\n answer += 1", "i", "range(N)", "range", "N", "if A[A[i]-1]-1 == i:\n answer += 1", "A[A[i]-1]-1 == i", "A[A[i]-1]-1", "A[A[i]-1]", "A", "A[i]-1", "A[i]", "A", "i", "1", "1", "i", "answer += 1", "answer", "1", "print(answer//2)", "print", "answer//2", "answer", "2", "rl = lambda: list(map(int, stdin.readline().split()))", "lambda: list(map(int, stdin.readline().split()))", "rl", "rs = lambda: stdin.readline().rstrip()", "lambda: stdin.readline().rstrip()", "rs", "answer = 0", "0", "answer", "stdin = sys.stdin", "sys.stdin", "stdin", "ri = lambda: int(rs())", "lambda: int(rs())", "ri", "answer += 1", "1", "answer", "N = ri()", "ri()", "N", "A = rl()", "rl()", "A" ]

[ 7, 15, 13, 13, 13, 13, 13, 13, 13, 13, 15, 13, 12, 13, 12, 13, 0, 13, 4, 13, 0, 13, 4, 13, 0, 13, 17, 28, 13, 13, 4, 13, 13, 17, 14, 2, 13, 17, 9, 14, 2, 18, 13, 2, 13, 17, 13, 0, 13, 17, 0, 18, 13, 2, 13, 17, 17, 4, 13, 13, 10, 17, 13, 10, 12, 13, 10, 17, 13, 10, 12, 13, 10, 4, 13, 10, 4, 13 ]

[ [ 76, 17 ], [ 65, 19 ], [ 73, 21 ], [ 71, 23 ], [ 67, 25 ], [ 74, 32 ], [ 74, 42 ], [ 61, 48 ], [ 56, 51 ], [ 74, 52 ], [ 62, 59 ], [ 68, 59 ], [ 61, 62 ], [ 67, 68 ], [ 73, 74 ], [ 76, 77 ] ]

[ "import bisect,collections,copy,heapq,itertools,math,numpy,string\nimport sys\ndef I(): return int(sys.stdin.readline().rstrip())\ndef LI(): return list(map(int,sys.stdin.readline().rstrip().split()))\nN = I()\na = LI()\nans = 0\nfor i,x in enumerate(a,1):\n if x=='*':\n continue\n if a[x-1]==i:\n ans += 1\n a[x-1] = '*'\nprint(ans)", "import bisect,collections,copy,heapq,itertools,math,numpy,string", "bisect", "collections", "copy", "heapq", "itertools", "math", "numpy", "string", "import sys", "sys", "def I(): return int(sys.stdin.readline().rstrip())", "I", "def LI(): return list(map(int,sys.stdin.readline().rstrip().split()))", "LI", "N = I()", "N", "I()", "I", "a = LI()", "a", "LI()", "LI", "ans = 0", "ans", "0", "for i,x in enumerate(a,1):\n if x=='*':\n continue\n if a[x-1]==i:\n ans += 1\n a[x-1] = '*'", "i", "x", "enumerate(a,1)", "enumerate", "a", "1", "if x=='*':\n continue\n ", "x=='*'", "x", "'*'", "continue", "if a[x-1]==i:\n ans += 1\n a[x-1] = '*'", "a[x-1]==i", "a[x-1]", "a", "x-1", "x", "1", "i", "ans += 1", "ans", "1", "a[x-1] = '*'", "a[x-1]", "a", "x-1", "x", "1", "'*'", "print(ans)", "print", "ans", "ans += 1", "1", "ans", "def I(): return int(sys.stdin.readline().rstrip())", "def I(): return int(sys.stdin.readline().rstrip())", "I", "ans = 0", "0", "ans", "def LI(): return list(map(int,sys.stdin.readline().rstrip().split()))", "def LI(): return list(map(int,sys.stdin.readline().rstrip().split()))", "LI", "a = LI()", "LI()", "a", "N = I()", "I()", "N" ]

[ 7, 15, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 4, 13, 13, 28, 13, 13, 4, 13, 13, 0, 13, 17, 0, 13, 2, 2, 4, 13, 4, 13, 13, 13, 17, 4, 13, 4, 13, 13, 13, 0, 18, 13, 13, 17, 0, 13, 17, 28, 13, 13, 4, 18, 13, 13, 14, 2, 13, 17, 0, 13, 17, 4, 13, 13, 10, 4, 13, 10, 4, 13, 10, 17, 13, 10, 17, 13, 10, 4, 13, 10, 2, 13 ]

[ [ 77, 3 ], [ 89, 9 ], [ 80, 21 ], [ 90, 30 ], [ 33, 32 ], [ 92, 35 ], [ 55, 52 ], [ 81, 53 ], [ 93, 54 ], [ 83, 57 ], [ 81, 64 ], [ 86, 71 ], [ 87, 75 ], [ 84, 75 ], [ 77, 78 ], [ 80, 81 ], [ 83, 84 ], [ 86, 87 ], [ 89, 90 ], [ 92, 93 ] ]

[ "from collections import defaultdict\n\nn = int(input())\nalst = list(map(int, input().split()))\ndd = defaultdict(int)\n\nfor i, num in enumerate(alst, start = 1):\n s = str(min(i, num)) + \"-\" + str(max(i, num))\n dd[s] += 1\n\nans = 0\nfor i, j in dd.items():\n if j == 2:\n ans += 1\nprint(ans)", "from collections import defaultdict", "n = int(input())", "n", "int(input())", "int", "input()", "input", "alst = list(map(int, input().split()))", "alst", "list(map(int, input().split()))", "list", "map(int, input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "dd = defaultdict(int)", "dd", "defaultdict(int)", "defaultdict", "int", "for i, num in enumerate(alst, start = 1):\n s = str(min(i, num)) + \"-\" + str(max(i, num))\n dd[s] += 1", "i", "num", "enumerate(alst, start = 1)", "enumerate", "alst", "start = 1", "start", "1", "s = str(min(i, num)) + \"-\" + str(max(i, num))", "s", "str(min(i, num)) + \"-\" + str(max(i, num))", "str(min(i, num)) + \"-\"", "str(min(i, num))", "str", "min(i, num)", "min", "i", "num", "\"-\"", "str(max(i, num))", "str", "max(i, num)", "max", "i", "num", "dd[s] += 1", "dd[s]", "dd", "s", "1", "ans = 0", "ans", "0", "for i, j in dd.items():\n if j == 2:\n ans += 1", "i", "j", "dd.items()", "dd.items", "dd", "items", "if j == 2:\n ans += 1", "j == 2", "j", "2", "ans += 1", "ans", "1", "print(ans)", "print", "ans", "n = int(input())", "int(input())", "n", "dd = defaultdict(int)", "defaultdict(int)", "dd", "ans = 0", "0", "ans", "ans += 1", "1", "ans", "alst = list(map(int, input().split()))", "list(map(int, input().split()))", "alst", "s = str(min(i, num)) + \"-\" + str(max(i, num))", "str(min(i, num)) + \"-\" + str(max(i, num))", "s" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 17, 28, 13, 4, 13, 13, 14, 2, 18, 13, 2, 18, 13, 13, 17, 2, 13, 17, 0, 13, 17, 4, 13, 2, 13, 17, 10, 4, 13, 10, 17, 13, 10, 4, 13, 10, 17, 13 ]

[ [ 54, 2 ], [ 48, 8 ], [ 51, 20 ], [ 24, 23 ], [ 55, 26 ], [ 49, 30 ], [ 49, 33 ], [ 23, 34 ], [ 23, 37 ], [ 57, 40 ], [ 58, 45 ], [ 52, 45 ], [ 48, 49 ], [ 51, 52 ], [ 54, 55 ], [ 57, 58 ] ]

[ "N=int(input())\na=list(map(int,input().split()))\n\nK=0\nfor i in range(N):\n if a[a[i]-1]==i+1:\n K+=1\nprint(K//2)", "N=int(input())", "N", "int(input())", "int", "input()", "input", "a=list(map(int,input().split()))", "a", "list(map(int,input().split()))", "list", "map(int,input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "K=0", "K", "0", "for i in range(N):\n if a[a[i]-1]==i+1:\n K+=1", "i", "range(N)", "range", "N", "if a[a[i]-1]==i+1:\n K+=1", "a[a[i]-1]==i+1", "a[a[i]-1]", "a", "a[i]-1", "a[i]", "a", "i", "1", "i+1", "i", "1", "K+=1", "K", "1", "print(K//2)", "print", "K//2", "K", "2", "a=list(map(int,input().split()))", "list(map(int,input().split()))", "a", "K=0", "0", "K", "N=int(input())", "int(input())", "N", "K+=1", "1", "K" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 39, 0, 13, 39, 28, 13, 4, 13, 13, 0, 13, 39, 18, 13, 13, 2, 13, 17, 4, 18, 13, 13, 4, 18, 13, 13, 2, 2, 18, 13, 17, 13, 18, 13, 17, 4, 13, 2, 4, 13, 13, 4, 13, 4, 13, 13, 10, 4, 13, 10, 4, 13, 10, 39, 13, 10, 39, 13, 10, 39, 13 ]

[ [ 68, 2 ], [ 71, 8 ], [ 80, 20 ], [ 74, 23 ], [ 27, 26 ], [ 69, 29 ], [ 77, 31 ], [ 72, 34 ], [ 26, 35 ], [ 26, 37 ], [ 78, 41 ], [ 75, 41 ], [ 81, 45 ], [ 78, 50 ], [ 75, 50 ], [ 69, 52 ], [ 78, 54 ], [ 75, 54 ], [ 81, 61 ], [ 81, 66 ], [ 68, 69 ], [ 71, 72 ], [ 74, 75 ], [ 77, 78 ], [ 80, 81 ] ]

[ "N=int(input())\na=list(map(int,input().split()))\nl=[]\nbuf=[]\nfor i in range(N):\n buf=[a[i],i+1]\n buf.sort()\n l.append(buf[0]*N+buf[1])\nprint(len(l)-len(set(l)))\n", "N=int(input())", "N", "int(input())", "int", "input()", "input", "a=list(map(int,input().split()))", "a", "list(map(int,input().split()))", "list", "map(int,input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "l=[]", "l", "[]", "buf=[]", "buf", "[]", "for i in range(N):\n buf=[a[i],i+1]\n buf.sort()\n l.append(buf[0]*N+buf[1])", "i", "range(N)", "range", "N", "buf=[a[i],i+1]", "buf", "[a[i],i+1]", "a[i]", "a", "i", "i+1", "i", "1", "buf.sort()", "buf.sort", "buf", "sort", "l.append(buf[0]*N+buf[1])", "l.append", "l", "append", "buf[0]*N+buf[1]", "buf[0]*N", "buf[0]", "buf", "0", "N", "buf[1]", "buf", "1", "print(len(l)-len(set(l)))", "print", "len(l)-len(set(l))", "len(l)", "len", "l", "len(set(l))", "len", "set(l)", "set", "l", "N=int(input())", "int(input())", "N", "a=list(map(int,input().split()))", "list(map(int,input().split()))", "a", "buf=[]", "[]", "buf", "buf=[a[i],i+1]", "[a[i],i+1]", "buf", "l=[]", "[]", "l" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 31, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 17, 0, 13, 17, 42, 2, 13, 13, 14, 2, 2, 13, 17, 18, 13, 2, 18, 13, 13, 17, 0, 13, 17, 0, 13, 17, 4, 13, 2, 13, 17, 10, 17, 13, 10, 4, 13, 10, 17, 13, 10, 17, 13, 10, 17, 13 ]

[ [ 55, 2 ], [ 10, 8 ], [ 58, 19 ], [ 52, 22 ], [ 59, 26 ], [ 65, 26 ], [ 56, 27 ], [ 59, 31 ], [ 65, 31 ], [ 59, 38 ], [ 65, 38 ], [ 61, 41 ], [ 64, 44 ], [ 62, 49 ], [ 53, 49 ], [ 52, 53 ], [ 55, 56 ], [ 58, 59 ], [ 61, 62 ], [ 64, 65 ] ]

[ "N=int(input())\n*A,=map(int,input().split())\ni=0\nans=0\nwhile i<N:\n if i+1==A[A[i]-1]:\n ans+=1\n i+=1\nprint(ans//2)", "N=int(input())", "N", "int(input())", "int", "input()", "input", "*A,=map(int,input().split())", "*A", "A", "map(int,input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "i=0", "i", "0", "ans=0", "ans", "0", "while i<N:\n if i+1==A[A[i]-1]:\n ans+=1\n i+=1", "i<N", "i", "N", "if i+1==A[A[i]-1]:\n ans+=1\n ", "i+1==A[A[i]-1]", "i+1", "i", "1", "A[A[i]-1]", "A", "A[i]-1", "A[i]", "A", "i", "1", "ans+=1", "ans", "1", "i+=1", "i", "1", "print(ans//2)", "print", "ans//2", "ans", "2", "ans=0", "0", "ans", "N=int(input())", "int(input())", "N", "i=0", "0", "i", "ans+=1", "1", "ans", "i+=1", "1", "i" ]

[ 7, 15, 13, 0, 13, 4, 13, 4, 13, 0, 13, 4, 18, 13, 13, 4, 18, 4, 13, 13, 0, 13, 18, 13, 13, 0, 13, 2, 13, 17, 0, 13, 17, 28, 13, 4, 13, 13, 0, 13, 18, 13, 13, 14, 2, 18, 13, 13, 13, 0, 13, 17, 4, 13, 2, 13, 17, 10, 2, 13, 10, 17, 13, 10, 4, 13, 10, 18, 13, 10, 4, 13, 10, 17, 13 ]

[ [ 64, 4 ], [ 70, 10 ], [ 22, 21 ], [ 58, 26 ], [ 71, 28 ], [ 61, 31 ], [ 35, 34 ], [ 65, 37 ], [ 67, 39 ], [ 59, 41 ], [ 71, 41 ], [ 34, 42 ], [ 59, 46 ], [ 71, 46 ], [ 68, 47 ], [ 34, 48 ], [ 73, 50 ], [ 74, 55 ], [ 62, 55 ], [ 58, 59 ], [ 61, 62 ], [ 64, 65 ], [ 67, 68 ], [ 70, 71 ], [ 73, 74 ] ]

[ "# from math import factorial,sqrt,ceil,gcd\n# from itertools import permutations as permus\n# from collections import deque,Counter\n# import re\n# from functools import lru_cache # 簡単メモ化 @lru_cache(maxsize=1000)\n# from decimal import Decimal, getcontext\n# # getcontext().prec = 1000\n# # eps = Decimal(10) ** (-100)\n\nimport numpy as np\n# import networkx as nx\n# from scipy.sparse.csgraph import shortest_path, dijkstra, floyd_warshall, bellman_ford, johnson\n# from scipy.sparse import csr_matrix\n# from scipy.special import comb\n\n# slist = \"abcdefghijklmnopqrstuvwxyz\"\nN = int(input())\narrA = np.array(input().split(),dtype=np.int64)\narrA = arrA -1\n\nans = 0\nfor i in range(N):\n num = arrA[i]\n if arrA[num]==i:\n ans += 1\n\nprint(ans//2)\n# print(*ans) # unpackして出力。間にスペースが入る\n# for row in board:\n# print(*row,sep=\"\") #unpackして間にスペース入れずに出力する\n# print(\"{:.10f}\".format(ans))\n# print(\"{:0=10d}\".format(ans))", "import numpy as np", "numpy", "N = int(input())", "N", "int(input())", "int", "input()", "input", "arrA = np.array(input().split(),dtype=np.int64)", "arrA", "np.array(input().split(),dtype=np.int64)", "np.array", "np", "array", "input().split()", "().split", "()", "input", "split", "dtype=np.int64", "dtype", "np.int64", "np", "int64", "arrA = arrA -1", "arrA", "arrA -1", "arrA", "1", "ans = 0", "ans", "0", "for i in range(N):\n num = arrA[i]\n if arrA[num]==i:\n ans += 1", "i", "range(N)", "range", "N", "num = arrA[i]", "num", "arrA[i]", "arrA", "i", "if arrA[num]==i:\n ans += 1", "arrA[num]==i", "arrA[num]", "arrA", "num", "i", "ans += 1", "ans", "1", "print(ans//2)", "print", "ans//2", "ans", "2", "arrA = arrA -1", "arrA -1", "arrA", "ans = 0", "0", "ans", "N = int(input())", "int(input())", "N", "num = arrA[i]", "arrA[i]", "num", "arrA = np.array(input().split(),dtype=np.int64)", "np.array(input().split(),dtype=np.int64)", "arrA", "ans += 1", "1", "ans" ]

[ 7, 15, 13, 0, 13, 18, 18, 13, 13, 13, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 17, 28, 13, 4, 13, 13, 14, 2, 2, 18, 13, 2, 18, 13, 13, 17, 17, 13, 0, 13, 17, 4, 13, 2, 13, 17, 10, 17, 13, 10, 4, 13, 10, 17, 13, 10, 4, 13, 10, 18, 13 ]

[ [ 69, 4 ], [ 66, 11 ], [ 70, 15 ], [ 60, 17 ], [ 70, 26 ], [ 63, 29 ], [ 33, 32 ], [ 67, 35 ], [ 61, 40 ], [ 61, 43 ], [ 32, 44 ], [ 32, 47 ], [ 57, 49 ], [ 58, 54 ], [ 64, 54 ], [ 57, 58 ], [ 60, 61 ], [ 63, 64 ], [ 66, 67 ], [ 69, 70 ] ]

[ "# n, m, l = map(int, input().split())\n\n# list_n = list(map(int, input().split()))\n\n# n = input()\n# list = [input() for i in range(N)\n\n# list = [[i for i in range(N)] for _ in range(M)]\n\nimport sys\ninput = sys.stdin.readline\n\nN = int(input())\nA = list(map(int, input().split()))\n\nans = 0\nfor i in range(N):\n if A[A[i] - 1] - 1 == i:\n ans += 1\nprint(ans//2)", "import sys", "sys", "input = sys.stdin.readline", "input", "sys.stdin.readline", "sys.stdin", "sys", "stdin", "readline", "N = int(input())", "N", "int(input())", "int", "input()", "input", "A = list(map(int, input().split()))", "A", "list(map(int, input().split()))", "list", "map(int, input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "ans = 0", "ans", "0", "for i in range(N):\n if A[A[i] - 1] - 1 == i:\n ans += 1", "i", "range(N)", "range", "N", "if A[A[i] - 1] - 1 == i:\n ans += 1", "A[A[i] - 1] - 1 == i", "A[A[i] - 1] - 1", "A[A[i] - 1]", "A", "A[i] - 1", "A[i]", "A", "i", "1", "1", "i", "ans += 1", "ans", "1", "print(ans//2)", "print", "ans//2", "ans", "2", "ans += 1", "1", "ans", "A = list(map(int, input().split()))", "list(map(int, input().split()))", "A", "ans = 0", "0", "ans", "N = int(input())", "int(input())", "N", "input = sys.stdin.readline", "sys.stdin.readline", "input" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 41, 28, 13, 4, 13, 13, 2, 2, 18, 13, 2, 18, 13, 13, 17, 17, 13, 4, 13, 0, 13, 13, 4, 13, 2, 4, 13, 13, 17, 10, 4, 13, 10, 13, 13, 10, 4, 13 ]

[ [ 55, 2 ], [ 49, 8 ], [ 22, 21 ], [ 56, 24 ], [ 50, 28 ], [ 50, 31 ], [ 21, 32 ], [ 21, 35 ], [ 21, 37 ], [ 52, 39 ], [ 53, 46 ], [ 49, 50 ], [ 52, 53 ], [ 55, 56 ] ]

[ "n=int(input())\na=list(map(int,input().split()))\ncnt=[i for i in range(n) if a[a[i]-1]-1==i]\nprint(len(cnt)//2)", "n=int(input())", "n", "int(input())", "int", "input()", "input", "a=list(map(int,input().split()))", "a", "list(map(int,input().split()))", "list", "map(int,input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "i for i in range(n) if a[a[i]-1]-1==i", "for i in range(n) if a[a[i]-1]-1==i", "i", "range(n)", "range", "n", "a[a[i]-1]-1==i", "a[a[i]-1]-1", "a[a[i]-1]", "a", "a[i]-1", "a[i]", "a", "i", "1", "1", "i", "if a[a[i]-1]-1==i", "i", "cnt=[i for i in range(n) if a[a[i]-1]-1==i]", "cnt", "[i for i in range(n) if a[a[i]-1]-1==i]", "print(len(cnt)//2)", "print", "len(cnt)//2", "len(cnt)", "len", "cnt", "2", "a=list(map(int,input().split()))", "list(map(int,input().split()))", "a", "cnt=[i for i in range(n) if a[a[i]-1]-1==i]", "[i for i in range(n) if a[a[i]-1]-1==i]", "cnt", "n=int(input())", "int(input())", "n" ]

[ 7, 15, 13, 13, 13, 13, 13, 13, 13, 13, 15, 13, 12, 13, 12, 13, 0, 13, 4, 13, 0, 13, 4, 13, 0, 13, 17, 0, 13, 17, 28, 13, 13, 4, 13, 13, 17, 0, 18, 13, 13, 13, 28, 13, 13, 4, 18, 13, 13, 14, 2, 13, 39, 18, 13, 13, 0, 13, 17, 4, 13, 2, 13, 17, 10, 4, 13, 10, 17, 13, 10, 17, 13, 10, 12, 13, 10, 12, 13, 10, 4, 13, 10, 17, 13 ]

[ [ 65, 17 ], [ 75, 19 ], [ 80, 21 ], [ 78, 23 ], [ 71, 25 ], [ 83, 28 ], [ 81, 35 ], [ 41, 38 ], [ 84, 39 ], [ 84, 47 ], [ 84, 54 ], [ 68, 57 ], [ 69, 62 ], [ 72, 62 ], [ 65, 66 ], [ 68, 69 ], [ 71, 72 ], [ 80, 81 ], [ 83, 84 ] ]

[ "import bisect,collections,copy,heapq,itertools,math,numpy,string\nimport sys\ndef I(): return int(sys.stdin.readline().rstrip())\ndef LI(): return list(map(int,sys.stdin.readline().rstrip().split()))\nN = I()\na = LI()\ncount = 0\na_dict = {}\nfor i,x in enumerate(a,1):\n a_dict[i] = x\nfor k,v in a_dict.items():\n if k in [a_dict[v]]:\n count +=1\nprint(count//2)", "import bisect,collections,copy,heapq,itertools,math,numpy,string", "bisect", "collections", "copy", "heapq", "itertools", "math", "numpy", "string", "import sys", "sys", "def I(): return int(sys.stdin.readline().rstrip())", "I", "def LI(): return list(map(int,sys.stdin.readline().rstrip().split()))", "LI", "N = I()", "N", "I()", "I", "a = LI()", "a", "LI()", "LI", "count = 0", "count", "0", "a_dict = {}", "a_dict", "{}", "for i,x in enumerate(a,1):\n a_dict[i] = x", "i", "x", "enumerate(a,1)", "enumerate", "a", "1", "a_dict[i] = x", "a_dict[i]", "a_dict", "i", "x", "for k,v in a_dict.items():\n if k in [a_dict[v]]:\n count +=1", "k", "v", "a_dict.items()", "a_dict.items", "a_dict", "items", "if k in [a_dict[v]]:\n count +=1", "k in [a_dict[v]]", "k", "[a_dict[v]]", "a_dict[v]", "a_dict", "v", "count +=1", "count", "1", "print(count//2)", "print", "count//2", "count", "2", "N = I()", "I()", "N", "count +=1", "1", "count", "count = 0", "0", "count", "def I(): return int(sys.stdin.readline().rstrip())", "def I(): return int(sys.stdin.readline().rstrip())", "I", "def LI(): return list(map(int,sys.stdin.readline().rstrip().split()))", "def LI(): return list(map(int,sys.stdin.readline().rstrip().split()))", "LI", "a = LI()", "LI()", "a", "a_dict = {}", "{}", "a_dict" ]

[ 7, 15, 13, 0, 13, 18, 18, 18, 13, 13, 13, 13, 0, 13, 18, 18, 18, 13, 13, 13, 13, 0, 13, 18, 18, 18, 13, 13, 13, 13, 4, 18, 13, 13, 2, 17, 17, 0, 13, 4, 13, 17, 0, 13, 2, 2, 17, 17, 17, 12, 13, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 17, 28, 13, 4, 13, 13, 14, 2, 13, 2, 18, 13, 2, 18, 13, 13, 17, 17, 0, 13, 17, 4, 13, 2, 13, 17, 14, 2, 13, 17, 4, 13, 10, 18, 13, 10, 18, 13, 10, 2, 13, 10, 4, 13, 10, 12, 13, 10, 18, 13 ]

[ [ 107, 4 ], [ 119, 13 ], [ 104, 22 ], [ 113, 38 ], [ 110, 43 ], [ 53, 52 ], [ 120, 56 ], [ 59, 58 ], [ 120, 67 ], [ 71, 70 ], [ 74, 73 ], [ 52, 76 ], [ 73, 79 ], [ 58, 82 ], [ 58, 85 ], [ 73, 86 ], [ 91, 90 ], [ 90, 95 ], [ 70, 95 ], [ 117, 102 ], [ 104, 105 ], [ 107, 108 ], [ 110, 111 ], [ 113, 114 ], [ 119, 120 ] ]

[ "import sys\nread = sys.stdin.buffer.read\nreadline = sys.stdin.buffer.readline\nreadlines = sys.stdin.buffer.readlines\nsys.setrecursionlimit(10 ** 8)\nINF = float('inf')\nMOD = 10 ** 9 + 7\n\ndef main():\n N = int(readline())\n A = list(map(int, readline().split()))\n ans = 0\n for i in range(N):\n if i==A[A[i]-1]-1:\n ans += 1\n print(ans//2)\n\n\nif __name__ == '__main__':\n main()", "import sys", "sys", "read = sys.stdin.buffer.read", "read", "sys.stdin.buffer.read", "sys.stdin.buffer", "sys.stdin", "sys", "stdin", "buffer", "read", "readline = sys.stdin.buffer.readline", "readline", "sys.stdin.buffer.readline", "sys.stdin.buffer", "sys.stdin", "sys", "stdin", "buffer", "readline", "readlines = sys.stdin.buffer.readlines", "readlines", "sys.stdin.buffer.readlines", "sys.stdin.buffer", "sys.stdin", "sys", "stdin", "buffer", "readlines", "sys.setrecursionlimit(10 ** 8)", "sys.setrecursionlimit", "sys", "setrecursionlimit", "10 ** 8", "10", "8", "INF = float('inf')", "INF", "float('inf')", "float", "'inf'", "MOD = 10 ** 9 + 7", "MOD", "10 ** 9 + 7", "10 ** 9", "10", "9", "7", "def main():\n N = int(readline())\n A = list(map(int, readline().split()))\n ans = 0\n for i in range(N):\n if i==A[A[i]-1]-1:\n ans += 1\n print(ans//2)", "main", "N = int(readline())", "N", "int(readline())", "int", "readline()", "readline", "A = list(map(int, readline().split()))", "A", "list(map(int, readline().split()))", "list", "map(int, readline().split())", "map", "int", "readline().split()", "().split", "()", "readline", "split", "ans = 0", "ans", "0", "for i in range(N):\n if i==A[A[i]-1]-1:\n ans += 1\n ", "i", "range(N)", "range", "N", "if i==A[A[i]-1]-1:\n ans += 1\n ", "i==A[A[i]-1]-1", "i", "A[A[i]-1]-1", "A[A[i]-1]", "A", "A[i]-1", "A[i]", "A", "i", "1", "1", "ans += 1", "ans", "1", "print(ans//2)", "print", "ans//2", "ans", "2", "if __name__ == '__main__':\n main()", "__name__ == '__main__'", "__name__", "'__main__'", "main()", "main", "readlines = sys.stdin.buffer.readlines", "sys.stdin.buffer.readlines", "readlines", "read = sys.stdin.buffer.read", "sys.stdin.buffer.read", "read", "MOD = 10 ** 9 + 7", "10 ** 9 + 7", "MOD", "INF = float('inf')", "float('inf')", "INF", "def main():\n N = int(readline())\n A = list(map(int, readline().split()))\n ans = 0\n for i in range(N):\n if i==A[A[i]-1]-1:\n ans += 1\n print(ans//2)", "def main():\n N = int(readline())\n A = list(map(int, readline().split()))\n ans = 0\n for i in range(N):\n if i==A[A[i]-1]-1:\n ans += 1\n print(ans//2)", "main", "readline = sys.stdin.buffer.readline", "sys.stdin.buffer.readline", "readline" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 4, 13, 0, 13, 17, 28, 13, 4, 13, 13, 14, 2, 18, 13, 2, 18, 13, 13, 17, 2, 13, 17, 0, 13, 17, 4, 13, 2, 13, 17, 10, 4, 13, 10, 4, 13, 10, 17, 13, 10, 4, 13, 10, 17, 13 ]

[ [ 52, 2 ], [ 55, 8 ], [ 61, 20 ], [ 58, 24 ], [ 28, 27 ], [ 53, 30 ], [ 56, 34 ], [ 56, 37 ], [ 27, 38 ], [ 27, 41 ], [ 64, 44 ], [ 65, 49 ], [ 59, 49 ], [ 52, 53 ], [ 55, 56 ], [ 58, 59 ], [ 61, 62 ], [ 64, 65 ] ]

[ "N = int(input())\na = list(map(int, input().split()))\nnum = set()\nans = 0\nfor i in range(N):\n # print(a[a[i]-1], a[i])\n if a[a[i]-1] == i+1:\n ans += 1\n\nprint(ans//2)", "N = int(input())", "N", "int(input())", "int", "input()", "input", "a = list(map(int, input().split()))", "a", "list(map(int, input().split()))", "list", "map(int, input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "num = set()", "num", "set()", "set", "ans = 0", "ans", "0", "for i in range(N):\n # print(a[a[i]-1], a[i])\n if a[a[i]-1] == i+1:\n ans += 1", "i", "range(N)", "range", "N", "if a[a[i]-1] == i+1:\n ans += 1", "a[a[i]-1] == i+1", "a[a[i]-1]", "a", "a[i]-1", "a[i]", "a", "i", "1", "i+1", "i", "1", "ans += 1", "ans", "1", "print(ans//2)", "print", "ans//2", "ans", "2", "N = int(input())", "int(input())", "N", "a = list(map(int, input().split()))", "list(map(int, input().split()))", "a", "ans = 0", "0", "ans", "num = set()", "set()", "num", "ans += 1", "1", "ans" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 4, 18, 13, 13, 17, 17, 0, 13, 17, 28, 13, 4, 13, 17, 2, 13, 17, 14, 2, 13, 18, 13, 18, 13, 13, 0, 13, 17, 0, 13, 17, 4, 13, 13, 10, 4, 13, 10, 17, 13, 10, 4, 13, 10, 17, 13, 10, 17, 13 ]

[ [ 60, 2 ], [ 54, 8 ], [ 55, 21 ], [ 66, 26 ], [ 30, 29 ], [ 61, 34 ], [ 29, 38 ], [ 55, 40 ], [ 55, 42 ], [ 29, 43 ], [ 63, 45 ], [ 57, 48 ], [ 58, 52 ], [ 64, 52 ], [ 67, 52 ], [ 54, 55 ], [ 57, 58 ], [ 60, 61 ], [ 63, 64 ], [ 66, 67 ] ]

[ "n = int(input())\na = list(map(int, input().split()))\na.insert(0, 0)\nans = 0\nfor i in range(1, n + 1):\n if i == a[a[i]]:\n ans += 1\nans //= 2\nprint(ans)", "n = int(input())", "n", "int(input())", "int", "input()", "input", "a = list(map(int, input().split()))", "a", "list(map(int, input().split()))", "list", "map(int, input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "a.insert(0, 0)", "a.insert", "a", "insert", "0", "0", "ans = 0", "ans", "0", "for i in range(1, n + 1):\n if i == a[a[i]]:\n ans += 1", "i", "range(1, n + 1)", "range", "1", "n + 1", "n", "1", "if i == a[a[i]]:\n ans += 1", "i == a[a[i]]", "i", "a[a[i]]", "a", "a[i]", "a", "i", "ans += 1", "ans", "1", "ans //= 2", "ans", "2", "print(ans)", "print", "ans", "a = list(map(int, input().split()))", "list(map(int, input().split()))", "a", "ans //= 2", "2", "ans", "n = int(input())", "int(input())", "n", "ans += 1", "1", "ans", "ans = 0", "0", "ans" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 2, 39, 17, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 17, 28, 13, 4, 13, 17, 2, 13, 17, 14, 2, 13, 18, 13, 18, 13, 13, 0, 13, 17, 0, 13, 17, 4, 13, 13, 10, 4, 13, 10, 17, 13, 10, 17, 13, 10, 17, 13, 10, 2, 13 ]

[ [ 51, 2 ], [ 63, 8 ], [ 60, 23 ], [ 27, 26 ], [ 52, 31 ], [ 26, 35 ], [ 64, 37 ], [ 64, 39 ], [ 26, 40 ], [ 54, 42 ], [ 57, 45 ], [ 58, 49 ], [ 55, 49 ], [ 61, 49 ], [ 51, 52 ], [ 54, 55 ], [ 57, 58 ], [ 60, 61 ], [ 63, 64 ] ]

[ "n = int(input())\na = [0] + list(map(int, input().split()))\ncnt = 0\nfor i in range(1, n + 1):\n if i == a[a[i]]:\n cnt += 1\ncnt //= 2\nprint(cnt)", "n = int(input())", "n", "int(input())", "int", "input()", "input", "a = [0] + list(map(int, input().split()))", "a", "[0] + list(map(int, input().split()))", "[0]", "0", "list(map(int, input().split()))", "list", "map(int, input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "cnt = 0", "cnt", "0", "for i in range(1, n + 1):\n if i == a[a[i]]:\n cnt += 1", "i", "range(1, n + 1)", "range", "1", "n + 1", "n", "1", "if i == a[a[i]]:\n cnt += 1", "i == a[a[i]]", "i", "a[a[i]]", "a", "a[i]", "a", "i", "cnt += 1", "cnt", "1", "cnt //= 2", "cnt", "2", "print(cnt)", "print", "cnt", "n = int(input())", "int(input())", "n", "cnt += 1", "1", "cnt", "cnt //= 2", "2", "cnt", "cnt = 0", "0", "cnt", "a = [0] + list(map(int, input().split()))", "[0] + list(map(int, input().split()))", "a" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 2, 39, 17, 13, 0, 13, 17, 28, 13, 4, 13, 13, 14, 2, 18, 13, 13, 17, 14, 2, 2, 18, 13, 2, 18, 13, 13, 17, 17, 13, 0, 13, 17, 0, 18, 13, 13, 17, 0, 18, 13, 2, 18, 13, 13, 17, 17, 4, 13, 13, 10, 17, 13, 10, 4, 13, 10, 2, 13, 10, 17, 13, 10, 4, 13 ]

[ [ 84, 2 ], [ 75, 8 ], [ 78, 20 ], [ 85, 24 ], [ 72, 26 ], [ 30, 29 ], [ 85, 32 ], [ 55, 35 ], [ 79, 36 ], [ 29, 37 ], [ 76, 43 ], [ 76, 46 ], [ 29, 47 ], [ 29, 50 ], [ 81, 52 ], [ 58, 55 ], [ 79, 56 ], [ 29, 57 ], [ 67, 60 ], [ 79, 61 ], [ 76, 64 ], [ 29, 65 ], [ 82, 70 ], [ 73, 70 ], [ 72, 73 ], [ 75, 76 ], [ 78, 79 ], [ 81, 82 ], [ 84, 85 ] ]

[ "n=int(input())\na=list(map(int,input().split()))\nflag=[0]*n\nans=0\nfor i in range(n):\n if flag[i]==0:\n if (a[a[i]-1]-1)==i:\n ans+=1\n flag[i]=1\n flag[a[i]-1]=1\nprint(ans)", "n=int(input())", "n", "int(input())", "int", "input()", "input", "a=list(map(int,input().split()))", "a", "list(map(int,input().split()))", "list", "map(int,input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "flag=[0]*n", "flag", "[0]*n", "[0]", "0", "n", "ans=0", "ans", "0", "for i in range(n):\n if flag[i]==0:\n if (a[a[i]-1]-1)==i:\n ans+=1\n flag[i]=1\n flag[a[i]-1]=1", "i", "range(n)", "range", "n", "if flag[i]==0:\n if (a[a[i]-1]-1)==i:\n ans+=1\n flag[i]=1\n flag[a[i]-1]=1", "flag[i]==0", "flag[i]", "flag", "i", "0", "if (a[a[i]-1]-1)==i:\n ans+=1\n flag[i]=1\n flag[a[i]-1]=1", "(a[a[i]-1]-1)==i", "a[a[i]-1]-1", "a[a[i]-1]", "a", "a[i]-1", "a[i]", "a", "i", "1", "1", "i", "ans+=1", "ans", "1", "flag[i]=1", "flag[i]", "flag", "i", "1", "flag[a[i]-1]=1", "flag[a[i]-1]", "flag", "a[i]-1", "a[i]", "a", "i", "1", "1", "print(ans)", "print", "ans", "ans=0", "0", "ans", "a=list(map(int,input().split()))", "list(map(int,input().split()))", "a", "flag=[0]*n", "[0]*n", "flag", "ans+=1", "1", "ans", "n=int(input())", "int(input())", "n" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 17, 28, 13, 4, 13, 13, 14, 2, 2, 13, 17, 18, 13, 2, 18, 13, 13, 17, 0, 13, 17, 4, 13, 2, 13, 17, 10, 17, 13, 10, 4, 13, 10, 17, 13, 10, 4, 13 ]

[ [ 57, 2 ], [ 51, 8 ], [ 54, 20 ], [ 24, 23 ], [ 58, 26 ], [ 23, 30 ], [ 52, 33 ], [ 52, 36 ], [ 23, 37 ], [ 48, 40 ], [ 49, 45 ], [ 55, 45 ], [ 48, 49 ], [ 51, 52 ], [ 54, 55 ], [ 57, 58 ] ]

[ "N = int(input())\nA = list(map(int,input().split()))\n\ncnt = 0\nfor n in range(N):\n if n+1 == A[A[n]-1]:\n cnt += 1\n\nprint(cnt//2)", "N = int(input())", "N", "int(input())", "int", "input()", "input", "A = list(map(int,input().split()))", "A", "list(map(int,input().split()))", "list", "map(int,input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "cnt = 0", "cnt", "0", "for n in range(N):\n if n+1 == A[A[n]-1]:\n cnt += 1", "n", "range(N)", "range", "N", "if n+1 == A[A[n]-1]:\n cnt += 1", "n+1 == A[A[n]-1]", "n+1", "n", "1", "A[A[n]-1]", "A", "A[n]-1", "A[n]", "A", "n", "1", "cnt += 1", "cnt", "1", "print(cnt//2)", "print", "cnt//2", "cnt", "2", "cnt += 1", "1", "cnt", "A = list(map(int,input().split()))", "list(map(int,input().split()))", "A", "cnt = 0", "0", "cnt", "N = int(input())", "int(input())", "N" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 4, 13, 13, 0, 13, 17, 28, 13, 4, 13, 4, 13, 13, 0, 13, 18, 13, 13, 14, 2, 18, 13, 2, 13, 17, 2, 13, 17, 0, 13, 17, 4, 13, 4, 13, 2, 13, 17, 10, 4, 13, 10, 4, 13, 10, 17, 13, 10, 4, 13, 10, 18, 13, 10, 17, 13 ]

[ [ 67, 2 ], [ 58, 8 ], [ 61, 18 ], [ 59, 21 ], [ 73, 23 ], [ 27, 26 ], [ 62, 31 ], [ 70, 33 ], [ 62, 35 ], [ 26, 36 ], [ 62, 40 ], [ 71, 42 ], [ 26, 45 ], [ 64, 48 ], [ 65, 55 ], [ 74, 55 ], [ 58, 59 ], [ 61, 62 ], [ 64, 65 ], [ 67, 68 ], [ 70, 71 ], [ 73, 74 ] ]

[ "N = int(input())\nAAA = map(int,input().split())\nAA = list(AAA)\ncount = 0\nfor i in range(len(AA)):\n a = AA[i]\n if AA[a-1] == i+1:\n count +=1\nprint(int(count/2))", "N = int(input())", "N", "int(input())", "int", "input()", "input", "AAA = map(int,input().split())", "AAA", "map(int,input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "AA = list(AAA)", "AA", "list(AAA)", "list", "AAA", "count = 0", "count", "0", "for i in range(len(AA)):\n a = AA[i]\n if AA[a-1] == i+1:\n count +=1", "i", "range(len(AA))", "range", "len(AA)", "len", "AA", "a = AA[i]", "a", "AA[i]", "AA", "i", "if AA[a-1] == i+1:\n count +=1", "AA[a-1] == i+1", "AA[a-1]", "AA", "a-1", "a", "1", "i+1", "i", "1", "count +=1", "count", "1", "print(int(count/2))", "print", "int(count/2)", "int", "count/2", "count", "2", "AAA = map(int,input().split())", "map(int,input().split())", "AAA", "AA = list(AAA)", "list(AAA)", "AA", "count +=1", "1", "count", "N = int(input())", "int(input())", "N", "a = AA[i]", "AA[i]", "a", "count = 0", "0", "count" ]

[ 7, 15, 13, 15, 12, 13, 0, 13, 18, 13, 13, 0, 13, 17, 0, 13, 4, 13, 17, 4, 18, 13, 13, 2, 17, 17, 12, 13, 12, 13, 12, 13, 12, 13, 12, 13, 12, 13, 12, 13, 12, 13, 0, 13, 4, 13, 0, 13, 4, 13, 0, 13, 17, 28, 13, 4, 13, 13, 14, 2, 18, 13, 18, 13, 13, 13, 0, 13, 17, 4, 2, 2, 13, 17, 17, 4, 13, 2, 13, 17, 14, 2, 13, 17, 4, 13, 10, 12, 13 ]

[ [ 8, 7 ], [ 13, 12 ], [ 16, 15 ], [ 44, 43 ], [ 29, 45 ], [ 48, 47 ], [ 39, 49 ], [ 52, 51 ], [ 55, 54 ], [ 43, 57 ], [ 47, 61 ], [ 47, 63 ], [ 54, 64 ], [ 54, 65 ], [ 68, 67 ], [ 67, 72 ], [ 51, 72 ], [ 67, 78 ], [ 51, 78 ], [ 88, 85 ] ]

[ "#!/usr/bin/env python3\n\nimport sys\nfrom typing import Any, Callable, Deque, Dict, List, Mapping, Optional, Sequence, Set, Tuple, TypeVar, Union\n# import time\n# import math, cmath\n# import numpy as np\n# import scipy.sparse.csgraph as cs # csgraph_from_dense(ndarray, null_value=inf), bellman_ford(G, return_predecessors=True), dijkstra, floyd_warshall\n# import random # random, uniform, randint, randrange, shuffle, sample\n# import string # ascii_lowercase, ascii_uppercase, ascii_letters, digits, hexdigits\n# import re # re.compile(pattern) => ptn obj; p.search(s), p.match(s), p.finditer(s) => match obj; p.sub(after, s)\n# from bisect import bisect_left, bisect_right # bisect_left(a, x, lo=0, hi=len(a)) returns i such that all(val<x for val in a[lo:i]) and all(val>-=x for val in a[i:hi]).\n# from collections import deque # deque class. deque(L): dq.append(x), dq.appendleft(x), dq.pop(), dq.popleft(), dq.rotate()\n# from collections import defaultdict # subclass of dict. defaultdict(facroty)\n# from collections import Counter # subclass of dict. Counter(iter): c.elements(), c.most_common(n), c.subtract(iter)\n# from datetime import date, datetime # date.today(), date(year,month,day) => date obj; datetime.now(), datetime(year,month,day,hour,second,microsecond) => datetime obj; subtraction => timedelta obj\n# from datetime.datetime import strptime # strptime('2019/01/01 10:05:20', '%Y/%m/%d/ %H:%M:%S') returns datetime obj\n# from datetime import timedelta # td.days, td.seconds, td.microseconds, td.total_seconds(). abs function is also available.\n# from copy import copy, deepcopy # use deepcopy to copy multi-dimentional matrix without reference\n# from functools import reduce # reduce(f, iter[, init])\n# from functools import lru_cache # @lrucache ...arguments of functions should be able to be keys of dict (e.g. list is not allowed)\n# from heapq import heapify, heappush, heappop # built-in list. heapify(L) changes list in-place to min-heap in O(n), heappush(heapL, x) and heappop(heapL) in O(lgn).\n# from heapq import _heapify_max, _heappop_max, _siftdown_max\n# from heapq import nlargest, nsmallest # nlargest(n, iter[, key]) returns k-largest-list in O(n+klgn).\n# from itertools import count, cycle, repeat # count(start[,step]), cycle(iter), repeat(elm[,n])\n# from itertools import groupby # [(k, list(g)) for k, g in groupby('000112')] returns [('0',['0','0','0']), ('1',['1','1']), ('2',['2'])]\n# from itertools import starmap # starmap(pow, [[2,5], [3,2]]) returns [32, 9]\n# from itertools import product, permutations # product(iter, repeat=n), permutations(iter[,r])\n# from itertools import combinations, combinations_with_replacement\n# from itertools import accumulate # accumulate(iter[, f])\n# from operator import itemgetter # itemgetter(1), itemgetter('key')\n# from fractions import Fraction # Fraction(a, b) => a / b ∈ Q. note: Fraction(0.1) do not returns Fraciton(1, 10). Fraction('0.1') returns Fraction(1, 10)\n\n\n\ndef main():\n Num = Union[int, float]\n mod = 1000000007 # 10^9+7\n inf = float('inf') # sys.float_info.max = 1.79e+308\n # inf = 2 ** 63 - 1 # (for fast JIT compile in PyPy) 9.22e+18\n sys.setrecursionlimit(10**6) # 1000 -> 1000000\n def input(): return sys.stdin.readline().rstrip()\n def ii(): return int(input())\n def isp(): return input().split()\n def mi(): return map(int, input().split())\n def mi_0(): return map(lambda x: int(x)-1, input().split())\n def lmi(): return list(map(int, input().split()))\n def lmi_0(): return list(map(lambda x: int(x)-1, input().split()))\n def li(): return list(input())\n # def _heappush_max(h, item): h.append(item); _siftdown_max(h, 0, len(h)-1)\n \n \n n = ii()\n L = lmi_0()\n\n cnt = 0\n for i in range(n):\n if L[L[i]] == i:\n cnt += 1\n assert cnt % 2 == 0\n print(cnt // 2)\n\n\nif __name__ == \"__main__\":\n main()", "import sys", "sys", "from typing import Any, Callable, Deque, Dict, List, Mapping, Optional, Sequence, Set, Tuple, TypeVar, Union", "def main():\n Num = Union[int, float]\n mod = 1000000007 # 10^9+7\n inf = float('inf') # sys.float_info.max = 1.79e+308\n # inf = 2 ** 63 - 1 # (for fast JIT compile in PyPy) 9.22e+18\n sys.setrecursionlimit(10**6) # 1000 -> 1000000\n def input(): return sys.stdin.readline().rstrip()\n def ii(): return int(input())\n def isp(): return input().split()\n def mi(): return map(int, input().split())\n def mi_0(): return map(lambda x: int(x)-1, input().split())\n def lmi(): return list(map(int, input().split()))\n def lmi_0(): return list(map(lambda x: int(x)-1, input().split()))\n def li(): return list(input())\n # def _heappush_max(h, item): h.append(item); _siftdown_max(h, 0, len(h)-1)\n \n \n n = ii()\n L = lmi_0()\n\n cnt = 0\n for i in range(n):\n if L[L[i]] == i:\n cnt += 1\n assert cnt % 2 == 0\n print(cnt // 2)", "main", "Num = Union[int, float]", "Num", "Union[int, float]", "Union", "int", "mod = 1000000007", "mod", "1000000007", "inf = float('inf')", "inf", "float('inf')", "float", "'inf'", "sys.setrecursionlimit(10**6)", "sys.setrecursionlimit", "sys", "setrecursionlimit", "10**6", "10", "6", "def input(): return sys.stdin.readline().rstrip()\n ", "input", "def ii(): return int(input())\n ", "ii", "def isp(): return input().split()\n ", "isp", "def mi(): return map(int, input().split())\n ", "mi", "def mi_0(): return map(lambda x: int(x)-1, input().split())\n ", "mi_0", "def lmi(): return list(map(int, input().split()))\n ", "lmi", "def lmi_0(): return list(map(lambda x: int(x)-1, input().split()))\n ", "lmi_0", "def li(): return list(input())\n # def _heappush_max(h, item): h.append(item); _siftdown_max(h, 0, len(h)-1)\n \n \n ", "li", "n = ii()", "n", "ii()", "ii", "L = lmi_0()", "L", "lmi_0()", "lmi_0", "cnt = 0", "cnt", "0", "for i in range(n):\n if L[L[i]] == i:\n cnt += 1\n ", "i", "range(n)", "range", "n", "if L[L[i]] == i:\n cnt += 1\n ", "L[L[i]] == i", "L[L[i]]", "L", "L[i]", "L", "i", "i", "cnt += 1", "cnt", "1", "assert cnt % 2 == 0", "cnt % 2 == 0", "cnt % 2", "cnt", "2", "0", "print(cnt // 2)", "print", "cnt // 2", "cnt", "2", "if __name__ == \"__main__\":\n main()", "__name__ == \"__main__\"", "__name__", "\"__main__\"", "main()", "main", "def main():\n Num = Union[int, float]\n mod = 1000000007 # 10^9+7\n inf = float('inf') # sys.float_info.max = 1.79e+308\n # inf = 2 ** 63 - 1 # (for fast JIT compile in PyPy) 9.22e+18\n sys.setrecursionlimit(10**6) # 1000 -> 1000000\n def input(): return sys.stdin.readline().rstrip()\n def ii(): return int(input())\n def isp(): return input().split()\n def mi(): return map(int, input().split())\n def mi_0(): return map(lambda x: int(x)-1, input().split())\n def lmi(): return list(map(int, input().split()))\n def lmi_0(): return list(map(lambda x: int(x)-1, input().split()))\n def li(): return list(input())\n # def _heappush_max(h, item): h.append(item); _siftdown_max(h, 0, len(h)-1)\n \n \n n = ii()\n L = lmi_0()\n\n cnt = 0\n for i in range(n):\n if L[L[i]] == i:\n cnt += 1\n assert cnt % 2 == 0\n print(cnt // 2)", "def main():\n Num = Union[int, float]\n mod = 1000000007 # 10^9+7\n inf = float('inf') # sys.float_info.max = 1.79e+308\n # inf = 2 ** 63 - 1 # (for fast JIT compile in PyPy) 9.22e+18\n sys.setrecursionlimit(10**6) # 1000 -> 1000000\n def input(): return sys.stdin.readline().rstrip()\n def ii(): return int(input())\n def isp(): return input().split()\n def mi(): return map(int, input().split())\n def mi_0(): return map(lambda x: int(x)-1, input().split())\n def lmi(): return list(map(int, input().split()))\n def lmi_0(): return list(map(lambda x: int(x)-1, input().split()))\n def li(): return list(input())\n # def _heappush_max(h, item): h.append(item); _siftdown_max(h, 0, len(h)-1)\n \n \n n = ii()\n L = lmi_0()\n\n cnt = 0\n for i in range(n):\n if L[L[i]] == i:\n cnt += 1\n assert cnt % 2 == 0\n print(cnt // 2)", "main" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 17, 28, 13, 13, 4, 13, 13, 14, 2, 2, 13, 17, 18, 13, 2, 13, 17, 0, 13, 17, 4, 13, 2, 13, 17, 10, 17, 13, 10, 4, 13, 10, 17, 13, 10, 4, 13 ]

[ [ 50, 2 ], [ 56, 8 ], [ 53, 20 ], [ 57, 27 ], [ 57, 34 ], [ 47, 39 ], [ 48, 44 ], [ 54, 44 ], [ 47, 48 ], [ 50, 51 ], [ 53, 54 ], [ 56, 57 ] ]

[ "a = int(input())\nl = list(map(int,input().split()))\nans = 0\nfor e , i in enumerate(l):\n\tif (e+1) == l[i-1]:\n\t\tans +=1\nprint(ans//2)", "a = int(input())", "a", "int(input())", "int", "input()", "input", "l = list(map(int,input().split()))", "l", "list(map(int,input().split()))", "list", "map(int,input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "ans = 0", "ans", "0", "for e , i in enumerate(l):\n\tif (e+1) == l[i-1]:\n\t\tans +=1", "e", "i", "enumerate(l)", "enumerate", "l", "if (e+1) == l[i-1]:\n\t\tans +=1", "(e+1) == l[i-1]", "e+1", "e", "1", "l[i-1]", "l", "i-1", "i", "1", "ans +=1", "ans", "1", "print(ans//2)", "print", "ans//2", "ans", "2", "ans +=1", "1", "ans", "a = int(input())", "int(input())", "a", "ans = 0", "0", "ans", "l = list(map(int,input().split()))", "list(map(int,input().split()))", "l" ]

[ 7, 12, 13, 0, 13, 4, 13, 4, 13, 41, 28, 13, 4, 18, 4, 13, 13, 4, 2, 4, 13, 13, 17, 0, 13, 13, 0, 13, 17, 28, 13, 4, 13, 13, 14, 2, 13, 18, 13, 18, 13, 13, 0, 13, 17, 4, 13, 2, 13, 17, 14, 2, 13, 17, 4, 13, 10, 12, 13 ]

[ [ 5, 4 ], [ 12, 11 ], [ 11, 21 ], [ 25, 24 ], [ 28, 27 ], [ 31, 30 ], [ 4, 33 ], [ 30, 36 ], [ 24, 38 ], [ 24, 40 ], [ 30, 41 ], [ 44, 43 ], [ 43, 48 ], [ 27, 48 ], [ 58, 55 ] ]

[ "def main():\n N = int(input())\n A = [int(x)-1 for x in input().split()]\n ans = 0\n for i in range(N):\n if i==A[A[i]]:\n ans += 1\n print(ans//2)\nif __name__ == '__main__':\n main()", "def main():\n N = int(input())\n A = [int(x)-1 for x in input().split()]\n ans = 0\n for i in range(N):\n if i==A[A[i]]:\n ans += 1\n print(ans//2)", "main", "N = int(input())", "N", "int(input())", "int", "input()", "input", "int(x)-1 for x in input().split()", "for x in input().split()", "x", "input().split()", "().split", "()", "input", "split", "for x in input().split()", "int(x)-1", "int(x)", "int", "x", "1", "A = [int(x)-1 for x in input().split()]", "A", "[int(x)-1 for x in input().split()]", "ans = 0", "ans", "0", "for i in range(N):\n if i==A[A[i]]:\n ans += 1\n ", "i", "range(N)", "range", "N", "if i==A[A[i]]:\n ans += 1\n ", "i==A[A[i]]", "i", "A[A[i]]", "A", "A[i]", "A", "i", "ans += 1", "ans", "1", "print(ans//2)", "print", "ans//2", "ans", "2", "if __name__ == '__main__':\n main()", "__name__ == '__main__'", "__name__", "'__main__'", "main()", "main", "def main():\n N = int(input())\n A = [int(x)-1 for x in input().split()]\n ans = 0\n for i in range(N):\n if i==A[A[i]]:\n ans += 1\n print(ans//2)", "def main():\n N = int(input())\n A = [int(x)-1 for x in input().split()]\n ans = 0\n for i in range(N):\n if i==A[A[i]]:\n ans += 1\n print(ans//2)", "main" ]

[ 7, 0, 13, 4, 13, 13, 4, 18, 4, 18, 4, 13, 17, 13, 13, 31, 13, 0, 13, 17, 28, 13, 4, 13, 13, 14, 2, 2, 18, 13, 2, 18, 13, 13, 17, 17, 13, 0, 13, 17, 4, 13, 2, 13, 17, 10, 4, 13, 10, 17, 13, 10, 17, 13 ]

[ [ 46, 2 ], [ 46, 15 ], [ 52, 18 ], [ 22, 21 ], [ 47, 24 ], [ 21, 33 ], [ 21, 36 ], [ 49, 38 ], [ 50, 43 ], [ 53, 43 ], [ 46, 47 ], [ 49, 50 ], [ 52, 53 ] ]

[ "#!/usr/bin/env python3\nn, *a = map(int, open(0).read().split())\nans = 0\nfor i in range(n):\n if a[a[i] - 1] - 1 == i:\n ans += 1\nprint(ans // 2)", "n, *a = map(int, open(0).read().split())", "n", "map(int, open(0).read().split())", "map", "int", "open(0).read().split()", "(0).read().split", "(0).read()", "(0).read", "(0)", "open", "0", "read", "split", "*a", "a", "ans = 0", "ans", "0", "for i in range(n):\n if a[a[i] - 1] - 1 == i:\n ans += 1", "i", "range(n)", "range", "n", "if a[a[i] - 1] - 1 == i:\n ans += 1", "a[a[i] - 1] - 1 == i", "a[a[i] - 1] - 1", "a[a[i] - 1]", "a", "a[i] - 1", "a[i]", "a", "i", "1", "1", "i", "ans += 1", "ans", "1", "print(ans // 2)", "print", "ans // 2", "ans", "2", "n, *a = map(int, open(0).read().split())", "map(int, open(0).read().split())", "n", "ans += 1", "1", "ans", "ans = 0", "0", "ans" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 17, 28, 13, 4, 13, 13, 14, 2, 18, 13, 13, 17, 14, 2, 2, 18, 13, 2, 18, 13, 13, 17, 17, 13, 0, 13, 17, 0, 18, 13, 2, 18, 13, 13, 17, 17, 0, 18, 13, 13, 17, 4, 13, 13, 10, 4, 13, 10, 4, 13, 10, 17, 13, 10, 17, 13 ]

[ [ 69, 2 ], [ 66, 8 ], [ 75, 20 ], [ 24, 23 ], [ 70, 26 ], [ 58, 29 ], [ 67, 30 ], [ 23, 31 ], [ 67, 37 ], [ 58, 39 ], [ 67, 40 ], [ 23, 41 ], [ 23, 44 ], [ 72, 46 ], [ 56, 49 ], [ 67, 50 ], [ 58, 52 ], [ 67, 53 ], [ 23, 54 ], [ 61, 58 ], [ 67, 59 ], [ 23, 60 ], [ 73, 64 ], [ 76, 64 ], [ 66, 67 ], [ 69, 70 ], [ 72, 73 ], [ 75, 76 ] ]

[ "n = int(input())\na = list(map(int,input().split()))\nc = 0\n\nfor i in range(n):\n if a[i] == -1:\n pass\n elif a[a[i] - 1] - 1 == i:\n c += 1\n a[a[i] - 1] = -1\n a[i] = -1\n else:\n pass\n\nprint(c)", "n = int(input())", "n", "int(input())", "int", "input()", "input", "a = list(map(int,input().split()))", "a", "list(map(int,input().split()))", "list", "map(int,input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "c = 0", "c", "0", "for i in range(n):\n if a[i] == -1:\n pass\n elif a[a[i] - 1] - 1 == i:\n c += 1\n a[a[i] - 1] = -1\n a[i] = -1\n else:\n pass", "i", "range(n)", "range", "n", "if a[i] == -1:\n pass\n elif a[a[i] - 1] - 1 == i:\n c += 1\n a[a[i] - 1] = -1\n a[i] = -1\n else:\n pass", "a[i] == -1", "a[i]", "a", "i", "-1", "elif a[a[i] - 1] - 1 == i:\n c += 1\n a[a[i] - 1] = -1\n a[i] = -1\n ", "a[a[i] - 1] - 1 == i", "a[a[i] - 1] - 1", "a[a[i] - 1]", "a", "a[i] - 1", "a[i]", "a", "i", "1", "1", "i", "c += 1", "c", "1", "a[a[i] - 1] = -1", "a[a[i] - 1]", "a", "a[i] - 1", "a[i]", "a", "i", "1", "-1", "a[i] = -1", "a[i]", "a", "i", "-1", "print(c)", "print", "c", "a = list(map(int,input().split()))", "list(map(int,input().split()))", "a", "n = int(input())", "int(input())", "n", "c += 1", "1", "c", "c = 0", "0", "c" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 17, 28, 13, 4, 13, 13, 14, 2, 18, 13, 13, 17, 9, 0, 13, 2, 18, 13, 13, 17, 14, 2, 18, 13, 13, 2, 13, 17, 0, 13, 17, 0, 18, 13, 13, 17, 4, 13, 13, 10, 4, 13, 10, 2, 13, 10, 17, 13, 10, 17, 13, 10, 4, 13 ]

[ [ 61, 2 ], [ 73, 8 ], [ 70, 20 ], [ 24, 23 ], [ 62, 26 ], [ 74, 30 ], [ 23, 31 ], [ 64, 35 ], [ 74, 38 ], [ 23, 39 ], [ 53, 43 ], [ 74, 44 ], [ 65, 45 ], [ 23, 47 ], [ 67, 50 ], [ 56, 53 ], [ 74, 54 ], [ 65, 55 ], [ 68, 59 ], [ 71, 59 ], [ 61, 62 ], [ 64, 65 ], [ 67, 68 ], [ 70, 71 ], [ 73, 74 ] ]

[ "N = int(input())\nlikes = list(map(int, input().split()))\ncnt = 0\nfor i in range(N):\n if likes[i] == -1:\n continue\n idx = likes[i]-1\n if likes[idx] == i + 1:\n cnt += 1\n likes[idx] = -1\nprint(cnt)", "N = int(input())", "N", "int(input())", "int", "input()", "input", "likes = list(map(int, input().split()))", "likes", "list(map(int, input().split()))", "list", "map(int, input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "cnt = 0", "cnt", "0", "for i in range(N):\n if likes[i] == -1:\n continue\n idx = likes[i]-1\n if likes[idx] == i + 1:\n cnt += 1\n likes[idx] = -1", "i", "range(N)", "range", "N", "if likes[i] == -1:\n continue\n ", "likes[i] == -1", "likes[i]", "likes", "i", "-1", "continue", "idx = likes[i]-1", "idx", "likes[i]-1", "likes[i]", "likes", "i", "1", "if likes[idx] == i + 1:\n cnt += 1\n likes[idx] = -1", "likes[idx] == i + 1", "likes[idx]", "likes", "idx", "i + 1", "i", "1", "cnt += 1", "cnt", "1", "likes[idx] = -1", "likes[idx]", "likes", "idx", "-1", "print(cnt)", "print", "cnt", "N = int(input())", "int(input())", "N", "idx = likes[i]-1", "likes[i]-1", "idx", "cnt += 1", "1", "cnt", "cnt = 0", "0", "cnt", "likes = list(map(int, input().split()))", "list(map(int, input().split()))", "likes" ]

[ 7, 15, 13, 0, 13, 18, 18, 13, 13, 13, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 17, 28, 13, 4, 13, 13, 0, 13, 18, 13, 13, 14, 2, 2, 13, 17, 18, 13, 2, 13, 17, 4, 13, 2, 13, 17, 10, 18, 13, 10, 4, 13, 10, 17, 13, 10, 4, 13, 10, 18, 13 ]

[ [ 57, 4 ], [ 66, 11 ], [ 58, 15 ], [ 60, 17 ], [ 58, 26 ], [ 63, 29 ], [ 33, 32 ], [ 67, 35 ], [ 69, 37 ], [ 61, 39 ], [ 32, 40 ], [ 32, 44 ], [ 61, 47 ], [ 70, 49 ], [ 64, 54 ], [ 57, 58 ], [ 60, 61 ], [ 63, 64 ], [ 66, 67 ], [ 69, 70 ] ]

[ "import sys\ninput = sys.stdin.readline\nN = int(input())\na = list(map(int, input().split()))\nres = 0\nfor x in range(N):\n y = a[x]\n if x + 1 == a[y - 1]: res += 1\nprint(res // 2)", "import sys", "sys", "input = sys.stdin.readline", "input", "sys.stdin.readline", "sys.stdin", "sys", "stdin", "readline", "N = int(input())", "N", "int(input())", "int", "input()", "input", "a = list(map(int, input().split()))", "a", "list(map(int, input().split()))", "list", "map(int, input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "res = 0", "res", "0", "for x in range(N):\n y = a[x]\n if x + 1 == a[y - 1]: res += 1", "x", "range(N)", "range", "N", "y = a[x]", "y", "a[x]", "a", "x", "if x + 1 == a[y - 1]: res +=", "x + 1 == a[y - 1]", "x + 1", "x", "1", "a[y - 1]", "a", "y - 1", "y", "1", "print(res // 2)", "print", "res // 2", "res", "2", "input = sys.stdin.readline", "sys.stdin.readline", "input", "a = list(map(int, input().split()))", "list(map(int, input().split()))", "a", "res = 0", "0", "res", "N = int(input())", "int(input())", "N", "y = a[x]", "a[x]", "y" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 17, 0, 13, 17, 28, 13, 4, 13, 4, 13, 13, 14, 2, 2, 2, 18, 13, 13, 17, 13, 2, 13, 2, 18, 13, 2, 18, 13, 13, 17, 17, 0, 13, 2, 13, 17, 4, 13, 13, 10, 4, 13, 10, 17, 13, 10, 2, 13, 10, 4, 13 ]

[ [ 59, 2 ], [ 68, 8 ], [ 62, 21 ], [ 25, 24 ], [ 69, 29 ], [ 69, 35 ], [ 24, 36 ], [ 24, 38 ], [ 24, 40 ], [ 69, 43 ], [ 69, 46 ], [ 24, 47 ], [ 65, 51 ], [ 63, 53 ], [ 66, 53 ], [ 66, 57 ], [ 63, 57 ], [ 59, 60 ], [ 62, 63 ], [ 65, 66 ], [ 68, 69 ] ]

[ "N=int(input())\na=list(map(int, input().split(\" \")))\n\ncount=0\n\nfor i in range(len(a)):\n if a[i]-1>i and i==a[a[i]-1]-1:\n count=count+1\n \nprint(count)", "N=int(input())", "N", "int(input())", "int", "input()", "input", "a=list(map(int, input().split(\" \")))", "a", "list(map(int, input().split(\" \")))", "list", "map(int, input().split(\" \"))", "map", "int", "input().split(\" \")", "().split", "()", "input", "split", "\" \"", "count=0", "count", "0", "for i in range(len(a)):\n if a[i]-1>i and i==a[a[i]-1]-1:\n count=count+1\n ", "i", "range(len(a))", "range", "len(a)", "len", "a", "if a[i]-1>i and i==a[a[i]-1]-1:\n count=count+1\n ", "a[i]-1>i and i==a[a[i]-1]-1", "a[i]-1>i", "a[i]-1", "a[i]", "a", "i", "1", "i", "i==a[a[i]-1]-1", "i", "a[a[i]-1]-1", "a[a[i]-1]", "a", "a[i]-1", "a[i]", "a", "i", "1", "1", "count=count+1", "count", "count+1", "count", "1", "print(count)", "print", "count", "N=int(input())", "int(input())", "N", "count=0", "0", "count", "count=count+1", "count+1", "count", "a=list(map(int, input().split(\" \")))", "list(map(int, input().split(\" \")))", "a" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 4, 18, 13, 13, 17, 17, 0, 13, 17, 28, 13, 4, 13, 17, 2, 13, 17, 14, 2, 18, 13, 18, 13, 13, 13, 0, 13, 17, 4, 13, 4, 13, 2, 13, 17, 10, 4, 13, 10, 4, 13, 10, 17, 13, 10, 17, 13 ]

[ [ 58, 2 ], [ 55, 8 ], [ 56, 21 ], [ 64, 26 ], [ 30, 29 ], [ 59, 34 ], [ 56, 39 ], [ 56, 41 ], [ 29, 42 ], [ 29, 43 ], [ 61, 45 ], [ 62, 52 ], [ 65, 52 ], [ 55, 56 ], [ 58, 59 ], [ 61, 62 ], [ 64, 65 ] ]

[ "N = int(input())\nA = list(map(int,input().split()))\nA.insert(0,0)\nans = 0\nfor i in range(1,N+1):\n if A[A[i]] == i:\n ans += 1\nprint(int(ans/2)) ", "N = int(input())", "N", "int(input())", "int", "input()", "input", "A = list(map(int,input().split()))", "A", "list(map(int,input().split()))", "list", "map(int,input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "A.insert(0,0)", "A.insert", "A", "insert", "0", "0", "ans = 0", "ans", "0", "for i in range(1,N+1):\n if A[A[i]] == i:\n ans += 1", "i", "range(1,N+1)", "range", "1", "N+1", "N", "1", "if A[A[i]] == i:\n ans += 1", "A[A[i]] == i", "A[A[i]]", "A", "A[i]", "A", "i", "i", "ans += 1", "ans", "1", "print(int(ans/2))", "print", "int(ans/2)", "int", "ans/2", "ans", "2", "A = list(map(int,input().split()))", "list(map(int,input().split()))", "A", "N = int(input())", "int(input())", "N", "ans += 1", "1", "ans", "ans = 0", "0", "ans" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 17, 28, 13, 13, 4, 13, 13, 14, 2, 2, 13, 17, 18, 13, 2, 13, 17, 0, 13, 17, 4, 13, 2, 13, 17, 10, 4, 13, 10, 17, 13, 10, 4, 13, 10, 17, 13 ]

[ [ 53, 2 ], [ 47, 8 ], [ 50, 20 ], [ 48, 27 ], [ 48, 34 ], [ 56, 39 ], [ 57, 44 ], [ 51, 44 ], [ 47, 48 ], [ 50, 51 ], [ 53, 54 ], [ 56, 57 ] ]

[ "N = int(input())\na = list(map(int, input().split()))\n\ncount = 0\nfor index, x in enumerate(a):\n # print (x)\n if index + 1 == a[x - 1]:\n count += 1\n\nprint (count // 2)", "N = int(input())", "N", "int(input())", "int", "input()", "input", "a = list(map(int, input().split()))", "a", "list(map(int, input().split()))", "list", "map(int, input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "count = 0", "count", "0", "for index, x in enumerate(a):\n # print (x)\n if index + 1 == a[x - 1]:\n count += 1", "index", "x", "enumerate(a)", "enumerate", "a", "if index + 1 == a[x - 1]:\n count += 1", "index + 1 == a[x - 1]", "index + 1", "index", "1", "a[x - 1]", "a", "x - 1", "x", "1", "count += 1", "count", "1", "print (count // 2)", "print", "count // 2", "count", "2", "a = list(map(int, input().split()))", "list(map(int, input().split()))", "a", "count = 0", "0", "count", "N = int(input())", "int(input())", "N", "count += 1", "1", "count" ]

[ 7, 15, 13, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 2, 4, 18, 13, 13, 13, 17, 0, 13, 17, 28, 13, 4, 13, 13, 14, 2, 18, 13, 18, 13, 13, 13, 0, 13, 17, 4, 13, 2, 13, 17, 10, 2, 13, 10, 4, 13, 10, 17, 13, 10, 17, 13, 10, 4, 13 ]

[ [ 58, 4 ], [ 67, 10 ], [ 55, 22 ], [ 68, 28 ], [ 61, 31 ], [ 35, 34 ], [ 59, 37 ], [ 56, 41 ], [ 68, 41 ], [ 56, 43 ], [ 68, 43 ], [ 34, 44 ], [ 34, 45 ], [ 64, 47 ], [ 65, 52 ], [ 62, 52 ], [ 55, 56 ], [ 58, 59 ], [ 61, 62 ], [ 64, 65 ], [ 67, 68 ] ]

[ "import numpy as np\nn = int(input())\na = list(map(int, input().split()))\na = np.array(a) - 1\n\nans = 0\nfor i in range(n):\n if a[a[i]] == i:\n ans += 1\n\nprint(ans // 2)", "import numpy as np", "numpy", "n = int(input())", "n", "int(input())", "int", "input()", "input", "a = list(map(int, input().split()))", "a", "list(map(int, input().split()))", "list", "map(int, input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "a = np.array(a) - 1", "a", "np.array(a) - 1", "np.array(a)", "np.array", "np", "array", "a", "1", "ans = 0", "ans", "0", "for i in range(n):\n if a[a[i]] == i:\n ans += 1", "i", "range(n)", "range", "n", "if a[a[i]] == i:\n ans += 1", "a[a[i]] == i", "a[a[i]]", "a", "a[i]", "a", "i", "i", "ans += 1", "ans", "1", "print(ans // 2)", "print", "ans // 2", "ans", "2", "a = np.array(a) - 1", "np.array(a) - 1", "a", "n = int(input())", "int(input())", "n", "ans = 0", "0", "ans", "ans += 1", "1", "ans", "a = list(map(int, input().split()))", "list(map(int, input().split()))", "a" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 17, 0, 13, 2, 39, 17, 13, 28, 13, 13, 4, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 14, 2, 18, 13, 2, 13, 17, 17, 14, 2, 18, 13, 2, 13, 17, 13, 4, 13, 13, 10, 17, 13, 10, 4, 13, 10, 2, 13 ]

[ [ 54, 2 ], [ 51, 8 ], [ 57, 11 ], [ 55, 15 ], [ 58, 34 ], [ 58, 42 ], [ 52, 49 ], [ 51, 52 ], [ 54, 55 ], [ 57, 58 ] ]

[ "n=int(input())\nans=0\ntable=[-1]*n\nfor i,j in enumerate(list(map(int,input().split()))):\n if table[j-1]==-1:table[i]=j-1\n elif table[j-1]==i:ans+=1\nprint(ans)", "n=int(input())", "n", "int(input())", "int", "input()", "input", "ans=0", "ans", "0", "table=[-1]*n", "table", "[-1]*n", "[-1]", "-1", "n", "for i,j in enumerate(list(map(int,input().split()))):\n if table[j-1]==-1:table[i]=j-1\n elif table[j-1]==i:ans+=1", "i", "j", "enumerate(list(map(int,input().split())))", "enumerate", "list(map(int,input().split()))", "list", "map(int,input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "if table[j-1]==-1:table[i]=j-1\n elif table[j-1]==i:ans+=1", "table[j-1]==-1", "table[j-1]", "table", "j-1", "j", "1", "-1", "elif table[j-1]==i:an", "table[j-1]==i", "table[j-1]", "table", "j-1", "j", "1", "i", "print(ans)", "print", "ans", "ans=0", "0", "ans", "n=int(input())", "int(input())", "n", "table=[-1]*n", "[-1]*n", "table" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 17, 41, 28, 13, 4, 13, 13, 4, 17, 0, 13, 13, 28, 13, 4, 13, 13, 14, 18, 13, 13, 9, 0, 18, 13, 13, 17, 14, 2, 2, 13, 17, 18, 13, 2, 18, 13, 13, 17, 0, 18, 13, 2, 18, 13, 13, 17, 17, 0, 13, 17, 4, 13, 13, 10, 4, 13, 10, 4, 13, 10, 17, 13, 10, 17, 13, 10, 13, 13 ]

[ [ 76, 2 ], [ 79, 8 ], [ 82, 20 ], [ 25, 24 ], [ 77, 27 ], [ 88, 31 ], [ 35, 34 ], [ 77, 37 ], [ 89, 40 ], [ 34, 41 ], [ 47, 44 ], [ 89, 45 ], [ 34, 46 ], [ 34, 51 ], [ 80, 54 ], [ 80, 57 ], [ 34, 58 ], [ 68, 61 ], [ 89, 62 ], [ 80, 65 ], [ 34, 66 ], [ 85, 70 ], [ 86, 74 ], [ 83, 74 ], [ 76, 77 ], [ 79, 80 ], [ 82, 83 ], [ 85, 86 ], [ 88, 89 ] ]

[ "n = int(input())\na = list(map(int, input().split()))\n\ncnt = 0\nchk = [False for i in range(n)]\nfor i in range(n):\n\tif chk[i]:\n\t\tcontinue\n\tchk[i] = True\n\tif i+1 == a[a[i]-1]:\n\t\tchk[a[i]-1] = True\n\t\tcnt += 1\nprint (cnt)", "n = int(input())", "n", "int(input())", "int", "input()", "input", "a = list(map(int, input().split()))", "a", "list(map(int, input().split()))", "list", "map(int, input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "cnt = 0", "cnt", "0", "False for i in range(n)", "for i in range(n)", "i", "range(n)", "range", "n", "for i in range(n)", "False", "chk = [False for i in range(n)]", "chk", "[False for i in range(n)]", "for i in range(n):\n\tif chk[i]:\n\t\tcontinue\n\tchk[i] = True\n\tif i+1 == a[a[i]-1]:\n\t\tchk[a[i]-1] = True\n\t\tcnt += 1", "i", "range(n)", "range", "n", "if chk[i]:\n\t\tcontinue\n\t", "chk[i]", "chk", "i", "continue", "chk[i] = True", "chk[i]", "chk", "i", "True", "if i+1 == a[a[i]-1]:\n\t\tchk[a[i]-1] = True\n\t\tcnt += 1", "i+1 == a[a[i]-1]", "i+1", "i", "1", "a[a[i]-1]", "a", "a[i]-1", "a[i]", "a", "i", "1", "chk[a[i]-1] = True", "chk[a[i]-1]", "chk", "a[i]-1", "a[i]", "a", "i", "1", "True", "cnt += 1", "cnt", "1", "print (cnt)", "print", "cnt", "n = int(input())", "int(input())", "n", "a = list(map(int, input().split()))", "list(map(int, input().split()))", "a", "cnt = 0", "0", "cnt", "cnt += 1", "1", "cnt", "chk = [False for i in range(n)]", "[False for i in range(n)]", "chk" ]

[ 7, 12, 13, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 17, 28, 13, 4, 13, 13, 14, 2, 2, 18, 13, 2, 18, 13, 13, 17, 17, 13, 0, 13, 17, 4, 13, 2, 13, 17, 29, 14, 2, 13, 17, 4, 13, 10, 12, 13 ]

[ [ 5, 4 ], [ 11, 10 ], [ 23, 22 ], [ 26, 25 ], [ 4, 28 ], [ 10, 33 ], [ 10, 36 ], [ 25, 37 ], [ 25, 40 ], [ 43, 42 ], [ 42, 47 ], [ 22, 47 ], [ 58, 55 ] ]

[ "def resolve():\n n = int(input())\n a = list(map(int, input().split()))\n ans = 0\n for i in range(n):\n if a[a[i]-1]-1 == i:\n ans += 1\n print(ans//2)\n return\n\nif __name__ == \"__main__\":\n resolve()", "def resolve():\n n = int(input())\n a = list(map(int, input().split()))\n ans = 0\n for i in range(n):\n if a[a[i]-1]-1 == i:\n ans += 1\n print(ans//2)\n return", "resolve", "n = int(input())", "n", "int(input())", "int", "input()", "input", "a = list(map(int, input().split()))", "a", "list(map(int, input().split()))", "list", "map(int, input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "ans = 0", "ans", "0", "for i in range(n):\n if a[a[i]-1]-1 == i:\n ans += 1\n ", "i", "range(n)", "range", "n", "if a[a[i]-1]-1 == i:\n ans += 1\n ", "a[a[i]-1]-1 == i", "a[a[i]-1]-1", "a[a[i]-1]", "a", "a[i]-1", "a[i]", "a", "i", "1", "1", "i", "ans += 1", "ans", "1", "print(ans//2)", "print", "ans//2", "ans", "2", "return", "if __name__ == \"__main__\":\n resolve()", "__name__ == \"__main__\"", "__name__", "\"__main__\"", "resolve()", "resolve", "def resolve():\n n = int(input())\n a = list(map(int, input().split()))\n ans = 0\n for i in range(n):\n if a[a[i]-1]-1 == i:\n ans += 1\n print(ans//2)\n return", "def resolve():\n n = int(input())\n a = list(map(int, input().split()))\n ans = 0\n for i in range(n):\n if a[a[i]-1]-1 == i:\n ans += 1\n print(ans//2)\n return", "resolve" ]

[ 7, 12, 13, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 17, 28, 13, 13, 4, 13, 13, 0, 13, 2, 13, 17, 0, 18, 13, 13, 13, 0, 13, 17, 28, 13, 4, 18, 13, 13, 14, 2, 18, 13, 18, 13, 13, 13, 0, 13, 17, 4, 13, 2, 13, 17, 14, 2, 13, 17, 4, 13, 10, 12, 13 ]

[ [ 5, 4 ], [ 11, 10 ], [ 23, 22 ], [ 10, 29 ], [ 32, 31 ], [ 31, 33 ], [ 39, 36 ], [ 22, 37 ], [ 31, 38 ], [ 42, 41 ], [ 45, 44 ], [ 22, 47 ], [ 22, 52 ], [ 22, 54 ], [ 44, 55 ], [ 44, 56 ], [ 59, 58 ], [ 58, 63 ], [ 41, 63 ], [ 73, 70 ] ]

[ "\ndef main():\n n = int(input())\n a_s = list(map(int,input().split()))\n dct = {}\n for i,value in enumerate(a_s):\n i = i+1\n dct[i] = value\n counter = 0\n for key in dct.keys():\n if dct[dct[key]] == key:\n counter += 1\n print(counter//2)\n\n\nif __name__ == '__main__':\n main()", "def main():\n n = int(input())\n a_s = list(map(int,input().split()))\n dct = {}\n for i,value in enumerate(a_s):\n i = i+1\n dct[i] = value\n counter = 0\n for key in dct.keys():\n if dct[dct[key]] == key:\n counter += 1\n print(counter//2)", "main", "n = int(input())", "n", "int(input())", "int", "input()", "input", "a_s = list(map(int,input().split()))", "a_s", "list(map(int,input().split()))", "list", "map(int,input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "dct = {}", "dct", "{}", "for i,value in enumerate(a_s):\n i = i+1\n dct[i] = value\n ", "i", "value", "enumerate(a_s)", "enumerate", "a_s", "i = i+1", "i", "i+1", "i", "1", "dct[i] = value", "dct[i]", "dct", "i", "value", "counter = 0", "counter", "0", "for key in dct.keys():\n if dct[dct[key]] == key:\n counter += 1\n ", "key", "dct.keys()", "dct.keys", "dct", "keys", "if dct[dct[key]] == key:\n counter += 1\n ", "dct[dct[key]] == key", "dct[dct[key]]", "dct", "dct[key]", "dct", "key", "key", "counter += 1", "counter", "1", "print(counter//2)", "print", "counter//2", "counter", "2", "if __name__ == '__main__':\n main()", "__name__ == '__main__'", "__name__", "'__main__'", "main()", "main", "def main():\n n = int(input())\n a_s = list(map(int,input().split()))\n dct = {}\n for i,value in enumerate(a_s):\n i = i+1\n dct[i] = value\n counter = 0\n for key in dct.keys():\n if dct[dct[key]] == key:\n counter += 1\n print(counter//2)", "def main():\n n = int(input())\n a_s = list(map(int,input().split()))\n dct = {}\n for i,value in enumerate(a_s):\n i = i+1\n dct[i] = value\n counter = 0\n for key in dct.keys():\n if dct[dct[key]] == key:\n counter += 1\n print(counter//2)", "main" ]

[ 7, 0, 13, 4, 13, 4, 13, 41, 28, 13, 4, 18, 4, 13, 13, 4, 4, 13, 13, 0, 13, 13, 0, 13, 17, 28, 13, 4, 13, 2, 13, 17, 14, 2, 13, 18, 13, 2, 18, 13, 2, 13, 17, 17, 0, 13, 17, 4, 13, 4, 13, 2, 13, 17, 10, 17, 13, 10, 17, 13, 10, 13, 13, 10, 4, 13 ]

[ [ 64, 2 ], [ 10, 9 ], [ 9, 18 ], [ 61, 20 ], [ 55, 23 ], [ 27, 26 ], [ 65, 30 ], [ 26, 34 ], [ 62, 36 ], [ 62, 39 ], [ 26, 41 ], [ 58, 45 ], [ 59, 52 ], [ 56, 52 ], [ 55, 56 ], [ 58, 59 ], [ 61, 62 ], [ 64, 65 ] ]

[ "n = int(input())\na = [int(x) for x in input().split()]\n\n# print(a)\n\n# print(n)\n# print(a)\ncount = 0\n\n\nfor i in range(n + 1):\n if(i == a[a[i - 1] - 1]):\n count += 1\n\n\nprint(int(count/2))", "n = int(input())", "n", "int(input())", "int", "input()", "input", "int(x) for x in input().split()", "for x in input().split()", "x", "input().split()", "().split", "()", "input", "split", "for x in input().split()", "int(x)", "int", "x", "a = [int(x) for x in input().split()]", "a", "[int(x) for x in input().split()]", "count = 0", "count", "0", "for i in range(n + 1):\n if(i == a[a[i - 1] - 1]):\n count += 1", "i", "range(n + 1)", "range", "n + 1", "n", "1", "if(i == a[a[i - 1] - 1]):\n count += 1", "i == a[a[i - 1] - 1]", "i", "a[a[i - 1] - 1]", "a", "a[i - 1] - 1", "a[i - 1]", "a", "i - 1", "i", "1", "1", "count += 1", "count", "1", "print(int(count/2))", "print", "int(count/2)", "int", "count/2", "count", "2", "count = 0", "0", "count", "count += 1", "1", "count", "a = [int(x) for x in input().split()]", "[int(x) for x in input().split()]", "a", "n = int(input())", "int(input())", "n" ]

[ 7, 0, 13, 4, 13, 4, 13, 41, 28, 13, 4, 18, 4, 13, 13, 4, 4, 13, 13, 0, 13, 13, 0, 13, 17, 0, 13, 4, 13, 28, 13, 4, 13, 13, 0, 13, 2, 13, 17, 0, 13, 18, 13, 13, 14, 2, 2, 39, 13, 13, 13, 2, 39, 13, 13, 13, 0, 13, 17, 4, 18, 13, 13, 39, 13, 13, 4, 18, 13, 13, 39, 13, 13, 4, 13, 13, 10, 18, 13, 10, 17, 13, 10, 4, 13, 10, 4, 13, 10, 13, 13, 10, 2, 13, 10, 17, 13 ]

[ [ 83, 2 ], [ 10, 9 ], [ 9, 18 ], [ 89, 20 ], [ 80, 23 ], [ 86, 26 ], [ 31, 30 ], [ 84, 33 ], [ 92, 35 ], [ 30, 37 ], [ 77, 40 ], [ 90, 42 ], [ 30, 43 ], [ 87, 50 ], [ 87, 55 ], [ 95, 57 ], [ 87, 61 ], [ 87, 68 ], [ 96, 75 ], [ 81, 75 ], [ 77, 78 ], [ 80, 81 ], [ 83, 84 ], [ 86, 87 ], [ 89, 90 ], [ 92, 93 ], [ 95, 96 ] ]

[ "# https://atcoder.jp/contests/code-festival-2016-quala/tasks/codefestival_2016_qualA_b\n\nn = int(input())\nnums = [int(i) for i in input().split()]\n\nans = 0\nd = set()\nfor i in range(n):\n a = i + 1\n b = nums[i]\n if (a, b) in d or (b, a) in d:\n ans += 1\n else:\n d.add((a, b))\n d.add((b, a))\nprint(ans)", "n = int(input())", "n", "int(input())", "int", "input()", "input", "int(i) for i in input().split()", "for i in input().split()", "i", "input().split()", "().split", "()", "input", "split", "for i in input().split()", "int(i)", "int", "i", "nums = [int(i) for i in input().split()]", "nums", "[int(i) for i in input().split()]", "ans = 0", "ans", "0", "d = set()", "d", "set()", "set", "for i in range(n):\n a = i + 1\n b = nums[i]\n if (a, b) in d or (b, a) in d:\n ans += 1\n else:\n d.add((a, b))\n d.add((b, a))", "i", "range(n)", "range", "n", "a = i + 1", "a", "i + 1", "i", "1", "b = nums[i]", "b", "nums[i]", "nums", "i", "if (a, b) in d or (b, a) in d:\n ans += 1\n else:\n d.add((a, b))\n d.add((b, a))", "(a, b) in d or (b, a) in d", "(a, b) in d", "(a, b)", "a", "b", "d", "(b, a) in d", "(b, a)", "b", "a", "d", "ans += 1", "ans", "1", "d.add((a, b))", "d.add", "d", "add", "(a, b)", "a", "b", "d.add((b, a))", "d.add", "d", "add", "(b, a)", "b", "a", "print(ans)", "print", "ans", "b = nums[i]", "nums[i]", "b", "ans = 0", "0", "ans", "n = int(input())", "int(input())", "n", "d = set()", "set()", "d", "nums = [int(i) for i in input().split()]", "[int(i) for i in input().split()]", "nums", "a = i + 1", "i + 1", "a", "ans += 1", "1", "ans" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 17, 28, 13, 4, 13, 13, 14, 2, 40, 18, 13, 13, 17, 2, 18, 13, 2, 18, 13, 13, 17, 2, 13, 17, 0, 13, 17, 0, 18, 13, 2, 18, 13, 13, 17, 17, 4, 13, 13, 10, 4, 13, 10, 4, 13, 10, 17, 13, 10, 17, 13 ]

[ [ 64, 2 ], [ 61, 8 ], [ 67, 20 ], [ 24, 23 ], [ 65, 26 ], [ 62, 31 ], [ 23, 32 ], [ 62, 36 ], [ 62, 39 ], [ 23, 40 ], [ 23, 43 ], [ 70, 46 ], [ 56, 49 ], [ 62, 50 ], [ 62, 53 ], [ 23, 54 ], [ 71, 59 ], [ 68, 59 ], [ 61, 62 ], [ 64, 65 ], [ 67, 68 ], [ 70, 71 ] ]

[ "n=int(input())\na=list(map(int,input().split()))\n\ncnt=0\nfor i in range(n):\n if a[i] >= 0 and a[a[i] - 1] == i + 1:\n cnt+=1\n a[a[i] - 1] = -1\nprint(cnt)", "n=int(input())", "n", "int(input())", "int", "input()", "input", "a=list(map(int,input().split()))", "a", "list(map(int,input().split()))", "list", "map(int,input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "cnt=0", "cnt", "0", "for i in range(n):\n if a[i] >= 0 and a[a[i] - 1] == i + 1:\n cnt+=1\n a[a[i] - 1] = -1", "i", "range(n)", "range", "n", "if a[i] >= 0 and a[a[i] - 1] == i + 1:\n cnt+=1\n a[a[i] - 1] = -1", "a[i] >= 0 and a[a[i] - 1] == i + 1", "a[i] >= 0", "a[i]", "a", "i", "0", "a[a[i] - 1] == i + 1", "a[a[i] - 1]", "a", "a[i] - 1", "a[i]", "a", "i", "1", "i + 1", "i", "1", "cnt+=1", "cnt", "1", "a[a[i] - 1] = -1", "a[a[i] - 1]", "a", "a[i] - 1", "a[i]", "a", "i", "1", "-1", "print(cnt)", "print", "cnt", "a=list(map(int,input().split()))", "list(map(int,input().split()))", "a", "n=int(input())", "int(input())", "n", "cnt=0", "0", "cnt", "cnt+=1", "1", "cnt" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 28, 13, 4, 13, 13, 0, 18, 13, 13, 2, 18, 13, 13, 17, 0, 13, 17, 28, 13, 4, 13, 13, 14, 2, 18, 13, 18, 13, 13, 13, 0, 13, 17, 4, 13, 2, 13, 17, 10, 4, 13, 10, 17, 13, 10, 17, 13, 10, 4, 13 ]

[ [ 67, 2 ], [ 58, 8 ], [ 21, 20 ], [ 68, 23 ], [ 28, 25 ], [ 59, 26 ], [ 20, 27 ], [ 25, 29 ], [ 59, 30 ], [ 20, 31 ], [ 64, 34 ], [ 38, 37 ], [ 68, 40 ], [ 59, 44 ], [ 25, 45 ], [ 59, 46 ], [ 37, 47 ], [ 37, 48 ], [ 61, 50 ], [ 62, 55 ], [ 65, 55 ], [ 58, 59 ], [ 61, 62 ], [ 64, 65 ], [ 67, 68 ] ]

[ "n=int(input())\na=list(map(int,input().split()))\nfor i in range(n):\n a[i]=a[i]-1\nc=0\nfor i in range(n):\n if a[a[i]]==i:\n c+=1\nprint(c//2)", "n=int(input())", "n", "int(input())", "int", "input()", "input", "a=list(map(int,input().split()))", "a", "list(map(int,input().split()))", "list", "map(int,input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "for i in range(n):\n a[i]=a[i]-1", "i", "range(n)", "range", "n", "a[i]=a[i]-1", "a[i]", "a", "i", "a[i]-1", "a[i]", "a", "i", "1", "c=0", "c", "0", "for i in range(n):\n if a[a[i]]==i:\n c+=1", "i", "range(n)", "range", "n", "if a[a[i]]==i:\n c+=1", "a[a[i]]==i", "a[a[i]]", "a", "a[i]", "a", "i", "i", "c+=1", "c", "1", "print(c//2)", "print", "c//2", "c", "2", "a=list(map(int,input().split()))", "list(map(int,input().split()))", "a", "c+=1", "1", "c", "c=0", "0", "c", "n=int(input())", "int(input())", "n" ]

[ 7, 15, 13, 4, 18, 13, 13, 2, 2, 17, 17, 17, 12, 13, 12, 13, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 17, 28, 13, 4, 13, 13, 14, 2, 18, 13, 2, 18, 13, 13, 17, 2, 13, 17, 0, 13, 17, 4, 13, 2, 13, 17, 4, 13, 10, 12, 13, 10, 12, 13 ]

[ [ 18, 17 ], [ 69, 21 ], [ 24, 23 ], [ 69, 32 ], [ 36, 35 ], [ 39, 38 ], [ 17, 41 ], [ 23, 45 ], [ 23, 48 ], [ 38, 49 ], [ 38, 52 ], [ 56, 55 ], [ 55, 60 ], [ 35, 60 ], [ 66, 63 ] ]

[ "import sys\nsys.setrecursionlimit(10 ** 5 + 10)\ndef input(): return sys.stdin.readline().strip()\n\ndef resolve():\n \n n=int(input())\n A=list(map(int,input().split()))\n cnt=0\n for i in range(n):\n if A[A[i]-1]==i+1:\n cnt+=1\n print(cnt//2) \nresolve()", "import sys", "sys", "sys.setrecursionlimit(10 ** 5 + 10)", "sys.setrecursionlimit", "sys", "setrecursionlimit", "10 ** 5 + 10", "10 ** 5", "10", "5", "10", "def input(): return sys.stdin.readline().strip()", "input", "def resolve():\n \n n=int(input())\n A=list(map(int,input().split()))\n cnt=0\n for i in range(n):\n if A[A[i]-1]==i+1:\n cnt+=1\n print(cnt//2) ", "resolve", "n=int(input())", "n", "int(input())", "int", "input()", "input", "A=list(map(int,input().split()))", "A", "list(map(int,input().split()))", "list", "map(int,input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "cnt=0", "cnt", "0", "for i in range(n):\n if A[A[i]-1]==i+1:\n cnt+=1\n ", "i", "range(n)", "range", "n", "if A[A[i]-1]==i+1:\n cnt+=1\n ", "A[A[i]-1]==i+1", "A[A[i]-1]", "A", "A[i]-1", "A[i]", "A", "i", "1", "i+1", "i", "1", "cnt+=1", "cnt", "1", "print(cnt//2)", "print", "cnt//2", "cnt", "2", "resolve()", "resolve", "def resolve():\n \n n=int(input())\n A=list(map(int,input().split()))\n cnt=0\n for i in range(n):\n if A[A[i]-1]==i+1:\n cnt+=1\n print(cnt//2) ", "def resolve():\n \n n=int(input())\n A=list(map(int,input().split()))\n cnt=0\n for i in range(n):\n if A[A[i]-1]==i+1:\n cnt+=1\n print(cnt//2) ", "resolve", "def input(): return sys.stdin.readline().strip()", "def input(): return sys.stdin.readline().strip()", "input" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 17, 28, 13, 4, 13, 4, 13, 13, 14, 2, 18, 13, 2, 18, 13, 13, 17, 2, 13, 17, 0, 13, 17, 4, 13, 2, 13, 17, 10, 17, 13, 10, 17, 13, 10, 4, 13, 10, 4, 13 ]

[ [ 59, 2 ], [ 56, 8 ], [ 53, 20 ], [ 24, 23 ], [ 57, 28 ], [ 57, 32 ], [ 57, 35 ], [ 23, 36 ], [ 23, 39 ], [ 50, 42 ], [ 51, 47 ], [ 54, 47 ], [ 50, 51 ], [ 53, 54 ], [ 56, 57 ], [ 59, 60 ] ]

[ "n=int(input())\na=list(map(int,input().split()))\ncnt=0\nfor i in range(len(a)):\n if a[a[i]-1]==i+1:\n cnt+=1\nprint(cnt//2)", "n=int(input())", "n", "int(input())", "int", "input()", "input", "a=list(map(int,input().split()))", "a", "list(map(int,input().split()))", "list", "map(int,input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "cnt=0", "cnt", "0", "for i in range(len(a)):\n if a[a[i]-1]==i+1:\n cnt+=1", "i", "range(len(a))", "range", "len(a)", "len", "a", "if a[a[i]-1]==i+1:\n cnt+=1", "a[a[i]-1]==i+1", "a[a[i]-1]", "a", "a[i]-1", "a[i]", "a", "i", "1", "i+1", "i", "1", "cnt+=1", "cnt", "1", "print(cnt//2)", "print", "cnt//2", "cnt", "2", "cnt+=1", "1", "cnt", "cnt=0", "0", "cnt", "a=list(map(int,input().split()))", "list(map(int,input().split()))", "a", "n=int(input())", "int(input())", "n" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 17, 28, 13, 4, 13, 13, 0, 13, 18, 13, 13, 0, 13, 18, 13, 2, 13, 17, 14, 2, 2, 13, 17, 13, 0, 13, 17, 0, 13, 17, 4, 13, 13, 10, 4, 13, 10, 18, 13, 10, 4, 13, 10, 18, 13, 10, 17, 13, 10, 17, 13, 10, 17, 13 ]

[ [ 55, 2 ], [ 61, 8 ], [ 73, 20 ], [ 24, 23 ], [ 56, 26 ], [ 58, 28 ], [ 62, 30 ], [ 23, 31 ], [ 64, 33 ], [ 62, 35 ], [ 59, 37 ], [ 23, 42 ], [ 65, 44 ], [ 70, 46 ], [ 67, 49 ], [ 68, 53 ], [ 71, 53 ], [ 74, 53 ], [ 55, 56 ], [ 58, 59 ], [ 61, 62 ], [ 64, 65 ], [ 67, 68 ], [ 70, 71 ], [ 73, 74 ] ]

[ "n=int(input())\na=list(map(int,input().split()))\nans=0\nfor i in range(n):\n b=a[i]\n c=a[b-1]\n if i+1==c:\n ans+=1\nans//=2\nprint(ans)", "n=int(input())", "n", "int(input())", "int", "input()", "input", "a=list(map(int,input().split()))", "a", "list(map(int,input().split()))", "list", "map(int,input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "ans=0", "ans", "0", "for i in range(n):\n b=a[i]\n c=a[b-1]\n if i+1==c:\n ans+=1", "i", "range(n)", "range", "n", "b=a[i]", "b", "a[i]", "a", "i", "c=a[b-1]", "c", "a[b-1]", "a", "b-1", "b", "1", "if i+1==c:\n ans+=1", "i+1==c", "i+1", "i", "1", "c", "ans+=1", "ans", "1", "ans//=2", "ans", "2", "print(ans)", "print", "ans", "n=int(input())", "int(input())", "n", "b=a[i]", "a[i]", "b", "a=list(map(int,input().split()))", "list(map(int,input().split()))", "a", "c=a[b-1]", "a[b-1]", "c", "ans//=2", "2", "ans", "ans+=1", "1", "ans", "ans=0", "0", "ans" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 17, 28, 13, 4, 13, 13, 14, 2, 2, 18, 13, 2, 18, 13, 13, 17, 2, 13, 17, 2, 18, 13, 13, 18, 13, 2, 18, 13, 2, 18, 13, 13, 17, 17, 0, 13, 17, 0, 18, 13, 2, 18, 13, 13, 17, 17, 0, 18, 13, 13, 17, 4, 13, 13, 10, 4, 13, 10, 17, 13, 10, 17, 13, 10, 4, 13 ]

[ [ 85, 2 ], [ 76, 8 ], [ 79, 20 ], [ 24, 23 ], [ 86, 26 ], [ 77, 31 ], [ 68, 33 ], [ 77, 34 ], [ 23, 35 ], [ 23, 38 ], [ 68, 41 ], [ 77, 42 ], [ 23, 43 ], [ 77, 45 ], [ 77, 48 ], [ 68, 50 ], [ 77, 51 ], [ 23, 52 ], [ 82, 56 ], [ 66, 59 ], [ 77, 60 ], [ 68, 62 ], [ 77, 63 ], [ 23, 64 ], [ 71, 68 ], [ 77, 69 ], [ 23, 70 ], [ 83, 74 ], [ 80, 74 ], [ 76, 77 ], [ 79, 80 ], [ 82, 83 ], [ 85, 86 ] ]

[ "n=int(input())\na=list(map(int,input().split()))\nans=0\nfor i in range(n):\n if a[a[i]-1]==i+1 and a[i]==a[a[a[i]-1]-1]:\n ans+=1\n a[a[i]-1]=0\n a[i]=0\nprint(ans)", "n=int(input())", "n", "int(input())", "int", "input()", "input", "a=list(map(int,input().split()))", "a", "list(map(int,input().split()))", "list", "map(int,input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "ans=0", "ans", "0", "for i in range(n):\n if a[a[i]-1]==i+1 and a[i]==a[a[a[i]-1]-1]:\n ans+=1\n a[a[i]-1]=0\n a[i]=0", "i", "range(n)", "range", "n", "if a[a[i]-1]==i+1 and a[i]==a[a[a[i]-1]-1]:\n ans+=1\n a[a[i]-1]=0\n a[i]=0", "a[a[i]-1]==i+1 and a[i]==a[a[a[i]-1]-1]", "a[a[i]-1]==i+1", "a[a[i]-1]", "a", "a[i]-1", "a[i]", "a", "i", "1", "i+1", "i", "1", "a[i]==a[a[a[i]-1]-1]", "a[i]", "a", "i", "a[a[a[i]-1]-1]", "a", "a[a[i]-1]-1", "a[a[i]-1]", "a", "a[i]-1", "a[i]", "a", "i", "1", "1", "ans+=1", "ans", "1", "a[a[i]-1]=0", "a[a[i]-1]", "a", "a[i]-1", "a[i]", "a", "i", "1", "0", "a[i]=0", "a[i]", "a", "i", "0", "print(ans)", "print", "ans", "a=list(map(int,input().split()))", "list(map(int,input().split()))", "a", "ans=0", "0", "ans", "ans+=1", "1", "ans", "n=int(input())", "int(input())", "n" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 2, 39, 17, 13, 0, 13, 17, 28, 13, 4, 13, 13, 14, 2, 18, 13, 13, 17, 14, 2, 18, 13, 2, 18, 13, 13, 17, 2, 13, 17, 0, 13, 17, 0, 18, 13, 2, 18, 13, 13, 17, 17, 4, 13, 13, 10, 4, 13, 10, 17, 13, 10, 2, 13, 10, 4, 13, 10, 17, 13 ]

[ [ 67, 2 ], [ 76, 8 ], [ 73, 20 ], [ 68, 24 ], [ 70, 26 ], [ 30, 29 ], [ 68, 32 ], [ 74, 36 ], [ 29, 37 ], [ 77, 42 ], [ 77, 45 ], [ 29, 46 ], [ 29, 49 ], [ 79, 52 ], [ 62, 55 ], [ 74, 56 ], [ 77, 59 ], [ 29, 60 ], [ 80, 65 ], [ 71, 65 ], [ 67, 68 ], [ 70, 71 ], [ 73, 74 ], [ 76, 77 ], [ 79, 80 ] ]

[ "n=int(input())\na=list(map(int,input().split()))\n\npair=[0]*n\n\ncnt=0\nfor i in range(n):\n if pair[i]==0:\n if a[a[i]-1]==i+1:\n cnt+=1\n pair[a[i]-1]=1\n\nprint(cnt)", "n=int(input())", "n", "int(input())", "int", "input()", "input", "a=list(map(int,input().split()))", "a", "list(map(int,input().split()))", "list", "map(int,input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "pair=[0]*n", "pair", "[0]*n", "[0]", "0", "n", "cnt=0", "cnt", "0", "for i in range(n):\n if pair[i]==0:\n if a[a[i]-1]==i+1:\n cnt+=1\n pair[a[i]-1]=1", "i", "range(n)", "range", "n", "if pair[i]==0:\n if a[a[i]-1]==i+1:\n cnt+=1\n pair[a[i]-1]=1", "pair[i]==0", "pair[i]", "pair", "i", "0", "if a[a[i]-1]==i+1:\n cnt+=1\n pair[a[i]-1]=1", "a[a[i]-1]==i+1", "a[a[i]-1]", "a", "a[i]-1", "a[i]", "a", "i", "1", "i+1", "i", "1", "cnt+=1", "cnt", "1", "pair[a[i]-1]=1", "pair[a[i]-1]", "pair", "a[i]-1", "a[i]", "a", "i", "1", "1", "print(cnt)", "print", "cnt", "n=int(input())", "int(input())", "n", "cnt=0", "0", "cnt", "pair=[0]*n", "[0]*n", "pair", "a=list(map(int,input().split()))", "list(map(int,input().split()))", "a", "cnt+=1", "1", "cnt" ]

[ 7, 15, 0, 13, 4, 13, 4, 13, 41, 28, 13, 4, 18, 4, 13, 13, 4, 4, 13, 13, 0, 13, 13, 0, 13, 4, 13, 13, 0, 13, 17, 28, 13, 4, 13, 13, 4, 18, 18, 13, 18, 13, 13, 13, 2, 13, 17, 14, 2, 18, 13, 13, 18, 13, 2, 13, 17, 0, 13, 17, 4, 13, 13, 10, 4, 13, 10, 4, 13, 10, 13, 13, 10, 17, 13, 10, 17, 13 ]

[ [ 64, 3 ], [ 11, 10 ], [ 10, 19 ], [ 70, 21 ], [ 67, 24 ], [ 73, 29 ], [ 33, 32 ], [ 65, 35 ], [ 68, 39 ], [ 71, 41 ], [ 32, 42 ], [ 32, 45 ], [ 71, 50 ], [ 32, 51 ], [ 68, 53 ], [ 32, 55 ], [ 76, 58 ], [ 77, 62 ], [ 74, 62 ], [ 64, 65 ], [ 67, 68 ], [ 70, 71 ], [ 73, 74 ], [ 76, 77 ] ]

[ "from collections import defaultdict\nn=int(input())\na=[int(i) for i in input().split()]\n\ndic = defaultdict(set)\nans=0\nfor i in range(n):\n dic[a[i]].add(i+1)\n if a[i] in dic[i+1]:\n ans+=1\nprint(ans)", "from collections import defaultdict", "n=int(input())", "n", "int(input())", "int", "input()", "input", "int(i) for i in input().split()", "for i in input().split()", "i", "input().split()", "().split", "()", "input", "split", "for i in input().split()", "int(i)", "int", "i", "a=[int(i) for i in input().split()]", "a", "[int(i) for i in input().split()]", "dic = defaultdict(set)", "dic", "defaultdict(set)", "defaultdict", "set", "ans=0", "ans", "0", "for i in range(n):\n dic[a[i]].add(i+1)\n if a[i] in dic[i+1]:\n ans+=1", "i", "range(n)", "range", "n", "dic[a[i]].add(i+1)", "[a[i]].add", "[a[i]]", "dic", "a[i]", "a", "i", "add", "i+1", "i", "1", "if a[i] in dic[i+1]:\n ans+=1", "a[i] in dic[i+1]", "a[i]", "a", "i", "dic[i+1]", "dic", "i+1", "i", "1", "ans+=1", "ans", "1", "print(ans)", "print", "ans", "n=int(input())", "int(input())", "n", "dic = defaultdict(set)", "defaultdict(set)", "dic", "a=[int(i) for i in input().split()]", "[int(i) for i in input().split()]", "a", "ans=0", "0", "ans", "ans+=1", "1", "ans" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 17, 28, 13, 4, 13, 13, 0, 13, 18, 13, 13, 14, 2, 18, 13, 2, 13, 17, 2, 13, 17, 0, 13, 17, 4, 13, 2, 13, 17, 10, 4, 13, 10, 4, 13, 10, 17, 13, 10, 18, 13, 10, 17, 13 ]

[ [ 54, 2 ], [ 51, 8 ], [ 57, 20 ], [ 24, 23 ], [ 55, 26 ], [ 60, 28 ], [ 52, 30 ], [ 23, 31 ], [ 52, 35 ], [ 61, 37 ], [ 23, 40 ], [ 63, 43 ], [ 64, 48 ], [ 58, 48 ], [ 51, 52 ], [ 54, 55 ], [ 57, 58 ], [ 60, 61 ], [ 63, 64 ] ]

[ "n = int(input())\nal = list(map(int, input().split()))\n\ncnt = 0\nfor i in range(n):\n j = al[i]\n if al[j-1] == i + 1:\n cnt += 1\n\nprint(cnt//2)", "n = int(input())", "n", "int(input())", "int", "input()", "input", "al = list(map(int, input().split()))", "al", "list(map(int, input().split()))", "list", "map(int, input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "cnt = 0", "cnt", "0", "for i in range(n):\n j = al[i]\n if al[j-1] == i + 1:\n cnt += 1", "i", "range(n)", "range", "n", "j = al[i]", "j", "al[i]", "al", "i", "if al[j-1] == i + 1:\n cnt += 1", "al[j-1] == i + 1", "al[j-1]", "al", "j-1", "j", "1", "i + 1", "i", "1", "cnt += 1", "cnt", "1", "print(cnt//2)", "print", "cnt//2", "cnt", "2", "al = list(map(int, input().split()))", "list(map(int, input().split()))", "al", "n = int(input())", "int(input())", "n", "cnt = 0", "0", "cnt", "j = al[i]", "al[i]", "j", "cnt += 1", "1", "cnt" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 17, 28, 13, 4, 13, 13, 14, 2, 18, 13, 13, 17, 9, 14, 2, 18, 13, 2, 18, 13, 13, 17, 2, 13, 17, 0, 18, 13, 2, 18, 13, 13, 17, 17, 0, 13, 17, 4, 13, 13, 10, 17, 13, 10, 4, 13, 10, 17, 13, 10, 4, 13 ]

[ [ 71, 2 ], [ 65, 8 ], [ 62, 20 ], [ 24, 23 ], [ 72, 26 ], [ 66, 30 ], [ 23, 31 ], [ 66, 37 ], [ 66, 40 ], [ 23, 41 ], [ 23, 44 ], [ 54, 47 ], [ 66, 48 ], [ 66, 51 ], [ 23, 52 ], [ 68, 56 ], [ 69, 60 ], [ 63, 60 ], [ 62, 63 ], [ 65, 66 ], [ 68, 69 ], [ 71, 72 ] ]

[ "n = int(input())\na = list(map(int , input().split()))\ncount = 0\nfor i in range(n):\n if a[i] == 0:\n continue\n if a[a[i] - 1] == i + 1:\n a[a[i] - 1] = 0\n count += 1\nprint(count)", "n = int(input())", "n", "int(input())", "int", "input()", "input", "a = list(map(int , input().split()))", "a", "list(map(int , input().split()))", "list", "map(int , input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "count = 0", "count", "0", "for i in range(n):\n if a[i] == 0:\n continue\n if a[a[i] - 1] == i + 1:\n a[a[i] - 1] = 0\n count += 1", "i", "range(n)", "range", "n", "if a[i] == 0:\n continue\n ", "a[i] == 0", "a[i]", "a", "i", "0", "continue", "if a[a[i] - 1] == i + 1:\n a[a[i] - 1] = 0\n count += 1", "a[a[i] - 1] == i + 1", "a[a[i] - 1]", "a", "a[i] - 1", "a[i]", "a", "i", "1", "i + 1", "i", "1", "a[a[i] - 1] = 0", "a[a[i] - 1]", "a", "a[i] - 1", "a[i]", "a", "i", "1", "0", "count += 1", "count", "1", "print(count)", "print", "count", "count = 0", "0", "count", "a = list(map(int , input().split()))", "list(map(int , input().split()))", "a", "count += 1", "1", "count", "n = int(input())", "int(input())", "n" ]

[ 7, 14, 2, 13, 17, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 17, 28, 13, 4, 13, 13, 14, 2, 2, 18, 13, 2, 18, 13, 13, 17, 17, 13, 0, 13, 17, 4, 13, 2, 13, 17, 10, 17, 13, 10, 4, 13, 10, 17, 13, 10, 4, 13 ]

[ [ 61, 6 ], [ 55, 12 ], [ 52, 24 ], [ 28, 27 ], [ 62, 30 ], [ 56, 35 ], [ 56, 38 ], [ 27, 39 ], [ 27, 42 ], [ 58, 44 ], [ 59, 49 ], [ 53, 49 ], [ 52, 53 ], [ 55, 56 ], [ 58, 59 ], [ 61, 62 ] ]

[ "if __name__ == \"__main__\":\n n = int(input())\n a = list(map(int, input().split()))\n\n ans = 0\n for i in range(n):\n if a[a[i]-1] - 1 == i:\n ans += 1\n\n print(ans//2)", "if __name__ == \"__main__\":\n n = int(input())\n a = list(map(int, input().split()))\n\n ans = 0\n for i in range(n):\n if a[a[i]-1] - 1 == i:\n ans += 1\n\n print(ans//2)", "__name__ == \"__main__\"", "__name__", "\"__main__\"", "n = int(input())", "n", "int(input())", "int", "input()", "input", "a = list(map(int, input().split()))", "a", "list(map(int, input().split()))", "list", "map(int, input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "ans = 0", "ans", "0", "for i in range(n):\n if a[a[i]-1] - 1 == i:\n ans += 1\n\n ", "i", "range(n)", "range", "n", "if a[a[i]-1] - 1 == i:\n ans += 1\n\n ", "a[a[i]-1] - 1 == i", "a[a[i]-1] - 1", "a[a[i]-1]", "a", "a[i]-1", "a[i]", "a", "i", "1", "1", "i", "ans += 1", "ans", "1", "print(ans//2)", "print", "ans//2", "ans", "2", "ans = 0", "0", "ans", "a = list(map(int, input().split()))", "list(map(int, input().split()))", "a", "ans += 1", "1", "ans", "n = int(input())", "int(input())", "n" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 17, 0, 13, 39, 28, 13, 4, 13, 13, 14, 2, 2, 13, 17, 18, 13, 2, 18, 13, 13, 17, 0, 13, 17, 4, 13, 4, 13, 2, 13, 17, 10, 17, 13, 10, 4, 13, 10, 39, 13, 10, 17, 13, 10, 4, 13 ]

[ [ 56, 2 ], [ 65, 8 ], [ 53, 20 ], [ 59, 23 ], [ 27, 26 ], [ 57, 29 ], [ 26, 33 ], [ 66, 36 ], [ 66, 39 ], [ 26, 40 ], [ 62, 43 ], [ 63, 50 ], [ 54, 50 ], [ 53, 54 ], [ 56, 57 ], [ 59, 60 ], [ 62, 63 ], [ 65, 66 ] ]

[ "N = int(input())\na_li = list(map(int, input().split()))\nans = 0\nchk = []\nfor i in range(N):\n if i + 1 == a_li[a_li[i] - 1] :\n ans += 1\nprint(int(ans / 2))", "N = int(input())", "N", "int(input())", "int", "input()", "input", "a_li = list(map(int, input().split()))", "a_li", "list(map(int, input().split()))", "list", "map(int, input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "ans = 0", "ans", "0", "chk = []", "chk", "[]", "for i in range(N):\n if i + 1 == a_li[a_li[i] - 1] :\n ans += 1", "i", "range(N)", "range", "N", "if i + 1 == a_li[a_li[i] - 1] :\n ans += 1", "i + 1 == a_li[a_li[i] - 1]", "i + 1", "i", "1", "a_li[a_li[i] - 1]", "a_li", "a_li[i] - 1", "a_li[i]", "a_li", "i", "1", "ans += 1", "ans", "1", "print(int(ans / 2))", "print", "int(ans / 2)", "int", "ans / 2", "ans", "2", "ans = 0", "0", "ans", "N = int(input())", "int(input())", "N", "chk = []", "[]", "chk", "ans += 1", "1", "ans", "a_li = list(map(int, input().split()))", "list(map(int, input().split()))", "a_li" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 2, 39, 17, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 41, 28, 13, 4, 13, 2, 13, 17, 4, 39, 0, 13, 13, 28, 13, 4, 13, 17, 2, 13, 17, 4, 18, 18, 13, 18, 13, 13, 13, 13, 0, 13, 17, 28, 13, 4, 13, 17, 2, 13, 17, 14, 2, 2, 18, 13, 13, 18, 13, 13, 2, 13, 18, 13, 18, 13, 13, 0, 13, 17, 4, 13, 2, 13, 17, 10, 17, 13, 10, 17, 13, 10, 13, 13, 10, 4, 13, 10, 2, 13 ]

[ [ 97, 2 ], [ 100, 8 ], [ 25, 24 ], [ 98, 28 ], [ 94, 33 ], [ 37, 36 ], [ 98, 41 ], [ 95, 46 ], [ 101, 48 ], [ 36, 49 ], [ 36, 51 ], [ 91, 53 ], [ 57, 56 ], [ 98, 61 ], [ 101, 67 ], [ 56, 68 ], [ 95, 70 ], [ 56, 71 ], [ 56, 73 ], [ 95, 75 ], [ 101, 77 ], [ 56, 78 ], [ 88, 80 ], [ 89, 85 ], [ 92, 85 ], [ 88, 89 ], [ 91, 92 ], [ 94, 95 ], [ 97, 98 ], [ 100, 101 ] ]

[ "n = int(input())\na = [0] + list(map(int, input().split()))\n\nG = [[] for _ in range(n + 1)]\n\nfor i in range(1, n + 1):\n\tG[a[i]].append(i)\n\ncnt = 0\nfor i in range(1, n + 1):\n\tif a[i] in G[i] and i in G[a[i]]:\n\t\tcnt += 1\nprint(cnt // 2)", "n = int(input())", "n", "int(input())", "int", "input()", "input", "a = [0] + list(map(int, input().split()))", "a", "[0] + list(map(int, input().split()))", "[0]", "0", "list(map(int, input().split()))", "list", "map(int, input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "[] for _ in range(n + 1)", "for _ in range(n + 1)", "_", "range(n + 1)", "range", "n + 1", "n", "1", "for _ in range(n + 1)", "[]", "G = [[] for _ in range(n + 1)]", "G", "[[] for _ in range(n + 1)]", "for i in range(1, n + 1):\n\tG[a[i]].append(i)", "i", "range(1, n + 1)", "range", "1", "n + 1", "n", "1", "G[a[i]].append(i)", "[a[i]].append", "[a[i]]", "G", "a[i]", "a", "i", "append", "i", "cnt = 0", "cnt", "0", "for i in range(1, n + 1):\n\tif a[i] in G[i] and i in G[a[i]]:\n\t\tcnt += 1", "i", "range(1, n + 1)", "range", "1", "n + 1", "n", "1", "if a[i] in G[i] and i in G[a[i]]:\n\t\tcnt += 1", "a[i] in G[i] and i in G[a[i]]", "a[i] in G[i]", "a[i]", "a", "i", "G[i]", "G", "i", "i in G[a[i]]", "i", "G[a[i]]", "G", "a[i]", "a", "i", "cnt += 1", "cnt", "1", "print(cnt // 2)", "print", "cnt // 2", "cnt", "2", "cnt += 1", "1", "cnt", "cnt = 0", "0", "cnt", "G = [[] for _ in range(n + 1)]", "[[] for _ in range(n + 1)]", "G", "n = int(input())", "int(input())", "n", "a = [0] + list(map(int, input().split()))", "[0] + list(map(int, input().split()))", "a" ]

[ 7, 0, 13, 4, 13, 4, 13, 41, 28, 13, 4, 18, 4, 13, 13, 4, 4, 13, 13, 0, 13, 13, 0, 13, 17, 0, 13, 17, 28, 13, 13, 4, 13, 13, 17, 0, 18, 13, 13, 13, 28, 13, 4, 13, 17, 2, 13, 17, 14, 2, 2, 18, 13, 13, 4, 18, 13, 13, 2, 18, 13, 18, 13, 13, 13, 0, 13, 17, 4, 13, 2, 13, 17, 10, 17, 13, 10, 17, 13, 10, 4, 13, 10, 17, 13, 10, 13, 13 ]

[ [ 80, 2 ], [ 10, 9 ], [ 9, 18 ], [ 86, 20 ], [ 83, 23 ], [ 77, 26 ], [ 87, 33 ], [ 39, 36 ], [ 84, 37 ], [ 42, 41 ], [ 81, 46 ], [ 36, 51 ], [ 84, 52 ], [ 41, 53 ], [ 84, 56 ], [ 84, 60 ], [ 36, 61 ], [ 84, 62 ], [ 41, 63 ], [ 41, 64 ], [ 74, 66 ], [ 75, 71 ], [ 78, 71 ], [ 74, 75 ], [ 77, 78 ], [ 80, 81 ], [ 83, 84 ], [ 86, 87 ] ]

[ "n = int(input())\nA = [int(x) for x in input().split()]\ndict = {}\nres = 0\nfor i, a in enumerate(A, 1):\n dict[i] = a\nfor i in range(1, n+1):\n if dict[i] in dict.keys() and dict[dict[i]] == i:\n res += 1\nprint(res // 2)", "n = int(input())", "n", "int(input())", "int", "input()", "input", "int(x) for x in input().split()", "for x in input().split()", "x", "input().split()", "().split", "()", "input", "split", "for x in input().split()", "int(x)", "int", "x", "A = [int(x) for x in input().split()]", "A", "[int(x) for x in input().split()]", "dict = {}", "dict", "{}", "res = 0", "res", "0", "for i, a in enumerate(A, 1):\n dict[i] = a", "i", "a", "enumerate(A, 1)", "enumerate", "A", "1", "dict[i] = a", "dict[i]", "dict", "i", "a", "for i in range(1, n+1):\n if dict[i] in dict.keys() and dict[dict[i]] == i:\n res += 1", "i", "range(1, n+1)", "range", "1", "n+1", "n", "1", "if dict[i] in dict.keys() and dict[dict[i]] == i:\n res += 1", "dict[i] in dict.keys() and dict[dict[i]] == i", "dict[i] in dict.keys()", "dict[i]", "dict", "i", "dict.keys()", "dict.keys", "dict", "keys", "dict[dict[i]] == i", "dict[dict[i]]", "dict", "dict[i]", "dict", "i", "i", "res += 1", "res", "1", "print(res // 2)", "print", "res // 2", "res", "2", "res += 1", "1", "res", "res = 0", "0", "res", "n = int(input())", "int(input())", "n", "dict = {}", "{}", "dict", "A = [int(x) for x in input().split()]", "[int(x) for x in input().split()]", "A" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 17, 28, 13, 13, 4, 13, 13, 14, 2, 13, 2, 18, 13, 2, 13, 17, 17, 0, 13, 17, 4, 13, 2, 13, 17, 10, 17, 13, 10, 4, 13, 10, 17, 13, 10, 4, 13 ]

[ [ 56, 2 ], [ 50, 8 ], [ 47, 20 ], [ 51, 27 ], [ 51, 33 ], [ 53, 39 ], [ 54, 44 ], [ 48, 44 ], [ 47, 48 ], [ 50, 51 ], [ 53, 54 ], [ 56, 57 ] ]

[ "N=int(input())\nA=list(map(int,input().split()))\ncnt=0\nfor idx,i in enumerate(A):\n if idx==A[i-1]-1:\n cnt+=1\nprint(cnt//2)\n", "N=int(input())", "N", "int(input())", "int", "input()", "input", "A=list(map(int,input().split()))", "A", "list(map(int,input().split()))", "list", "map(int,input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "cnt=0", "cnt", "0", "for idx,i in enumerate(A):\n if idx==A[i-1]-1:\n cnt+=1", "idx", "i", "enumerate(A)", "enumerate", "A", "if idx==A[i-1]-1:\n cnt+=1", "idx==A[i-1]-1", "idx", "A[i-1]-1", "A[i-1]", "A", "i-1", "i", "1", "1", "cnt+=1", "cnt", "1", "print(cnt//2)", "print", "cnt//2", "cnt", "2", "cnt=0", "0", "cnt", "A=list(map(int,input().split()))", "list(map(int,input().split()))", "A", "cnt+=1", "1", "cnt", "N=int(input())", "int(input())", "N" ]

[ 7, 15, 13, 12, 13, 0, 13, 18, 18, 13, 13, 13, 0, 13, 4, 13, 4, 13, 0, 13, 17, 41, 28, 13, 4, 18, 4, 13, 13, 4, 4, 13, 13, 0, 13, 13, 28, 13, 13, 4, 13, 13, 14, 2, 18, 13, 2, 13, 17, 2, 13, 17, 4, 13, 2, 13, 17, 29, 17, 14, 2, 13, 17, 4, 13, 10, 12, 13 ]

[ [ 7, 6 ], [ 14, 13 ], [ 6, 17 ], [ 20, 19 ], [ 24, 23 ], [ 6, 27 ], [ 23, 32 ], [ 35, 34 ], [ 34, 41 ], [ 34, 45 ], [ 19, 55 ], [ 67, 64 ] ]

[ "import sys\n\ndef solve():\n input = sys.stdin.readline\n N = int(input())\n pair = 0\n A = [int(a) for a in input().split()]\n for i, a in enumerate(A):\n if A[a-1] == i + 1: pair += 1\n print(pair // 2)\n\n return 0\n\nif __name__ ==\"__main__\":\n solve()", "import sys", "sys", "def solve():\n input = sys.stdin.readline\n N = int(input())\n pair = 0\n A = [int(a) for a in input().split()]\n for i, a in enumerate(A):\n if A[a-1] == i + 1: pair += 1\n print(pair // 2)\n\n return 0", "solve", "input = sys.stdin.readline", "input", "sys.stdin.readline", "sys.stdin", "sys", "stdin", "readline", "N = int(input())", "N", "int(input())", "int", "input()", "input", "pair = 0", "pair", "0", "int(a) for a in input().split()", "for a in input().split()", "a", "input().split()", "().split", "()", "input", "split", "for a in input().split()", "int(a)", "int", "a", "A = [int(a) for a in input().split()]", "A", "[int(a) for a in input().split()]", "for i, a in enumerate(A):\n if A[a-1] == i + 1: pair += 1\n ", "i", "a", "enumerate(A)", "enumerate", "A", "if A[a-1] == i + 1: pair += 1\n ", "A[a-1] == i + 1", "A[a-1]", "A", "a-1", "a", "1", "i + 1", "i", "1", "print(pair // 2)", "print", "pair // 2", "pair", "2", "return 0", "0", "if __name__ ==\"__main__\":\n solve()", "__name__ ==\"__main__\"", "__name__", "\"__main__\"", "solve()", "solve", "def solve():\n input = sys.stdin.readline\n N = int(input())\n pair = 0\n A = [int(a) for a in input().split()]\n for i, a in enumerate(A):\n if A[a-1] == i + 1: pair += 1\n print(pair // 2)\n\n return 0", "def solve():\n input = sys.stdin.readline\n N = int(input())\n pair = 0\n A = [int(a) for a in input().split()]\n for i, a in enumerate(A):\n if A[a-1] == i + 1: pair += 1\n print(pair // 2)\n\n return 0", "solve" ]

[ 7, 0, 13, 4, 13, 4, 13, 0, 13, 4, 13, 4, 13, 13, 4, 18, 4, 13, 13, 0, 13, 17, 28, 13, 4, 13, 17, 2, 13, 17, 0, 13, 18, 13, 2, 13, 17, 14, 2, 2, 13, 13, 2, 18, 13, 2, 13, 17, 13, 0, 13, 17, 4, 13, 13, 10, 17, 13, 10, 17, 13, 10, 4, 13, 10, 4, 13, 10, 18, 13 ]

[ [ 65, 2 ], [ 62, 8 ], [ 59, 20 ], [ 24, 23 ], [ 66, 28 ], [ 68, 31 ], [ 63, 33 ], [ 23, 35 ], [ 69, 40 ], [ 23, 41 ], [ 63, 44 ], [ 69, 46 ], [ 23, 48 ], [ 56, 50 ], [ 57, 54 ], [ 60, 54 ], [ 56, 57 ], [ 59, 60 ], [ 62, 63 ], [ 65, 66 ], [ 68, 69 ] ]

[ "N = int(input())\nA = list(map(int, input().split()))\nans = 0\nfor i in range(1, N+1):\n j = A[i-1]\n if j > i and A[j-1] == i:\n ans += 1\nprint(ans)", "N = int(input())", "N", "int(input())", "int", "input()", "input", "A = list(map(int, input().split()))", "A", "list(map(int, input().split()))", "list", "map(int, input().split())", "map", "int", "input().split()", "().split", "()", "input", "split", "ans = 0", "ans", "0", "for i in range(1, N+1):\n j = A[i-1]\n if j > i and A[j-1] == i:\n ans += 1", "i", "range(1, N+1)", "range", "1", "N+1", "N", "1", "j = A[i-1]", "j", "A[i-1]", "A", "i-1", "i", "1", "if j > i and A[j-1] == i:\n ans += 1", "j > i and A[j-1] == i", "j > i", "j", "i", "A[j-1] == i", "A[j-1]", "A", "j-1", "j", "1", "i", "ans += 1", "ans", "1", "print(ans)", "print", "ans", "ans += 1", "1", "ans", "ans = 0", "0", "ans", "A = list(map(int, input().split()))", "list(map(int, input().split()))", "A", "N = int(input())", "int(input())", "N", "j = A[i-1]", "A[i-1]", "j" ]