#include <bits/stdc++.h>
using namespace std;
using ll = long long;

int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(0);

	int n;
	cin >> n;

	// Select set S, |S| = n / 2
	// Count edges inside S twice
	// Count edges from S to outside S once
	// -> Vertex adds sarr of its edge-neighbours to the answer!

	ll tot = 0;
	vector<ll> sarr(n, 0);
	for (int i = 0; i < n; ++i) {
		for (int j = 0; j < n; ++j) {
			ll v;
			cin >> v;
			sarr[i] += v;
			tot += v;
		}
	}
	tot /= 2;

	ll maxv = 0;
	sort(sarr.rbegin(), sarr.rend());
	for (int i = 0; i < n / 2; ++i) maxv += sarr[i];
	cout << maxv - tot << '\n';
}