#include <iostream>
#include<bits/stdc++.h>
using namespace std;
int main() {
// your code goes here
int n ; int m ;
cin>>n;cin>>m;
int dp[n+m+1][n+1];
for(int i = 0 ; i<=n+m;i++){
for(int j = 0;j<=n;j++){
if(i==j || j==0) {
dp[i][j]=1;
}
else if(j>i || i==0){
dp[i][j]=0;
}
else{
dp[i][j]=dp[i-1][j]+dp[i-1][j-1];
}
}
}
cout<<dp[n+m][n];
return 0;
}
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