prefix sum of the two-dimensional array

// prefix sum of the two-dimensional array
#include<bits/stdc++.h>
using namespace std;
int main() {
    int n,m;cin>>n>>m;
    int ar[n][m],pfs[n][m];
    pfs[0][0]=0;
    for(int i=1;i<=n;i++){
        for(int j=1;j<=m;j++){
            cin>>ar[i][j];
            pfs[i][j]=ar[i][j]+pfs[i-1][j]+pfs[i][j-1]-pfs[i-1][j-1];
        }
    }

    int q,a,b,c,d;cin>>q;
    while(q--){
        cin>>a>>b>>c>>d;
        cout<<pfs[c][d]-pfs[a-1][d]-pfs[c][b-1]+pfs[a-1][b-1]<<endl;
    }

    return 0;
}