#include<bits/stdc++.h>
using namespace std;
int n,m,s;
void dfs(int x, int y)
{
    if(x==n&&y==m)s++;
    else
    {
        if(y<m)dfs(x,y+1);
        if(x<n)dfs(x+1,y);
    }
}
int main()
{
    cin>>n>>m;
    dfs(0,0);
    cout<<s;
    return 0;
}