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