//
// Created by 54173 on 5/23/2022.
//
#include <bits/stdc++.h>
using namespace std;

#define rep(i, a, b) for (int i = (a); i < (b); i++)
#define all(x) begin(x), end(x)
#define sz(x) (int)(x).size()
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef long long ll;
typedef pair<long long, long long> pll;

int main() {
    int n; cin>>n;
    int a[n][n];
    vector<pll> v;
    ll ans = 0;
    for(int i=0;i<n;i++) {
        ll sum = 0;
        for(int j=0;j<n;j++) {
            cin>>a[i][j];
            sum += a[i][j];
        }
        v.push_back({sum,i});
    }
    sort(v.begin(),v.end());
    //Make two group
    for(int i=0;i<n/2;i++) {
        for(int j=0;j<n/2;j++){
            int idx1 = v[i].second;
            int idx2 = v[j].second;
            ans -= a[idx1][idx2];
        }
    }
    for(int i=n/2;i<n;i++) {
        for(int j=n/2;j<n;j++){
            int idx1 = v[i].second;
            int idx2 = v[j].second;
            ans += a[idx1][idx2];
        }
    }
    cout<<ans/2;
    return 0;
}