import java.util.Scanner; public class A {     public static void main(String[] args) { Scanner in = new Scanner(System.in);      int n = in.nextInt();       int m = in.nextInt();         System.out.println(sum(n, m));     }          static int sum(int n, int m) {         if (m < 0)             return 0;         if (m == 0)             return 1;         if (m > 0 && n <= 0)             return 0;         int sum = 0;         for (int i = 1; i <= n; i++) {             sum += sum(i - 1, m - i);         }         return sum;     } }