#include <iostream>

using namespace std;

int m, n;

const int N = 110;
int a[N][N];

//动态规划 DP
int main() {
    cin >> m >> n;
    //初始化
    for (int i = 1; i <= n; i++) a[1][i] = 1;
    for (int i = 1; i <= m; i++) a[i][1] = 1;
    //找规律，两者和
    for (int i = 2; i <= m; i++)
        for (int j = 2; j <= n; j++)
            a[i][j] = a[i][j - 1] + a[i - 1][j];

    printf("%d", a[m][n]);
    return 0;
}