#include <iostream>

using namespace std;

long long n, d[100000];

int main() {

    int m;
    cin >> n >> m;
    int k[n][m];
    int cnt = 0;
    k[1][0] = 1;

    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= m; j++)
            k[i][j] = k[i - 1][j] + k[i][j - 1];

    cout << k[n][m];

    return 0;
}