Update app.py

app.py

@@ -16,7 +16,8 @@ def reverse_parameters(arg1:str, arg2:int)-> str: #it's import to specify the re
         arg1: the first argument
         arg2: the second argument
     """
-    return (arg1+' '+arg2)[][-1]
+    return_value = arg1+' '+arg2
+    return return_value[][-1]
 
 @tool
 def get_current_time_in_timezone(timezone: str) -> str: