repeated-string.py

#!/bin/python3

import sys

def repeatedString(s, n):
    return s.count('a') * (n//len(s)) + s[:n%len(s)].count('a')

if __name__ == "__main__":
    s = input().strip()
    n = int(input().strip())
    result = repeatedString(s, n)
    print(result)