#include<iostream>
using namespace std;
int n,m;
int ans;
void sfp(int x,int y)
{
if(x==n&&y==m)
ans++;
else
{
if(y<m)sfp(x,y+1);
if(x<n)sfp(x+1,y);
}
}
int main()
{
cin >> n >> m;
sfp(0,0);
cout << ans << endl;
return 0;
}