Update prompts.yaml

prompts.yaml

@@ -10,7 +10,7 @@
   YOUR FINAL ANSWER should be a number OR as few words as possible OR a comma separated list of numbers and/or strings.
   If you are asked for a number, don't use comma to write your number neither use units such as $ or
   percent sign unless specified otherwise.
-  If you are asked for a string, don't use articles, neither abbreviations (e.g. for cities - Saint Petersburg), and write the
+  If you are asked for a string, don't use articles, neither abbreviations (e.g. for cities - Saint Petersburg, NOT St.Petersburg), and write the
   digits in plain text unless specified otherwise.
   If you are asked for a comma separated list, apply the above rules depending of whether the element
   to be put in the list is a number or a string.