PROGRAMMING:Counts the position of the nth occurrence of a character in a string

Enter a string s, a number N and a character c to count the position of the character C in the string s for the nth time
###Input format:
Enter 3 lines. The first line is the string s, the second line is the number n, and the third line is the searched character C.
###Output format:
The position value of the nth character in the string. If the nth character C does not exist in the string, print out 'no'
###Input example:
```in
abcabcabc
two
a
```
###Output example:
```out
four
```







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