#include <iostream>

using namespace std;

int n,m;
int ans = 0; //定义在函数内的话，每次递归都会重置

int dfs(int x, int y)
{

    if(x == n && y == m) ans++;
    else
    {
        if(y < m) dfs(x,y+1);
        if(x < n) dfs(x+1,y);
    }
    return ans;
}

int main()
{
    cin >> n >> m;

    cout << dfs(0,0) << endl;;

    return 0;
}