class Result {

    private static final IntPredicate isA = c -> c == 'a';

    public static long repeatedString(String s, long n) {
      long times = n / s.length();
      long remainingChars = n % s.length();
      long count = s.chars().filter(isA).count();
      count*=times;  
      count += s.substring(0, (int) remainingChars).chars().filter(isA).count();  
      return count;
    }

}