C++ :

#include<cstdio>
int n,m,sum,cnt;
void dfs(int x,int y,int sum)
{
    if(x==0&&y==1&&sum==1)
    {
        cnt++;
        return ;
    }
    if(x>0) dfs(x-1,y,2*sum);
    if(y>0) dfs(x,y-1,sum-1);
}
int main()
{
    while(~scanf("%d%d",&n,&m))
    {
        cnt=0;
        dfs(n,m,2);
        printf("%d\n",cnt);
    }
    return 0;
}