public class Factorials {

    public static void main(String[] args) throws IOException {
        BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
        String str = in.readLine();
        StringTokenizer st = new StringTokenizer(str, " ");

        int n = Integer.parseInt(st.nextToken());
        int k = st.nextToken().length();

        if (n >= 1 && n <= 10) {
            if (k >= 1 && k <= 20) {
                int limite= n % k, total = n, res= 0, i = 1;
                do {
                    res= (n - (k * i));
                    if (res== 0) {
                        System.out.print(total);
                        return;
                    }
                    total *= res;
                    i++;
                } while (res!= limite);
                System.out.print(total);
            }
        }
    }
}

Edited by author 19.09.2015 06:20