深搜题解

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