SUM-test01

#include<bits/stdc++.h>
#define int long long
using namespace std;

int n, ans = 0;
signed main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    freopen("SUM.inp", "r", stdin);
    freopen("SUM.out", "w", stdout);
    cin >> n;
    int a[n][n];
    for(int i = 0; i < n; i++){
        for(int j = 0; j < n; j++) cin >> a[i][j];
    }
    int sum;

    for(int i = 0; i < n; i++){
        sum = 0;
        int k = i;
        for(int j = 0 ; j < n; j++){
            if(k<n) sum += a[k++][j];
        }
        if(ans < sum) ans = sum;
    }
    for(int j = 1; j < n; j++){
        sum = 0;
        int k = j;
        for(int i = 0 ; i < n; i++){
            if(k<n) sum += a[i][k++];
        }
        if(ans < sum) ans = sum;
    }
    cout << ans;
    return 0;
}