#include<iostream>
using namespace std;
int n,m;
int ans;
void 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);
}
}
int main()
{
cin>>n >> m;
dfs(0,0);
cout <<ans << endl;
return 0;
}