#include <bits/stdc++.h>
#define ll long long
#define mp make_pair
#define fi first
#define se second
#define pb push_back
#define vi vector<int>
#define pi pair<int, int>
#define maxn 2005
#define mod 998244353
template<typename T> bool chkmin(T &a, T b){return (b < a) ? a = b, 1 : 0;}
template<typename T> bool chkmax(T &a, T b){return (b > a) ? a = b, 1 : 0;}
ll ksm(ll a, ll b) {if (b == 0) return 1; ll ns = ksm(a, b >> 1); ns = ns * ns % mod; if (b & 1) ns = ns * a % mod; return ns;}
using namespace std;
int n;
int c[maxn][maxn];
int main() {
    cin >> n;
    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= n; j++)
            cin >> c[i][j];
    vector<pi> cur;
    for (int i = 1; i <= n; i++) {
        int sum = 0;
        for (int j = 1; j <= n; j++)
            sum += c[i][j];
        cur.pb(mp(sum, i));
    }
    sort(cur.begin(), cur.end());
    int k = n / 2;
    int ans = 0;
    for (int i = 0; i < n; i++) {
        if (i < k) ans += cur[i].fi;
        else ans -= cur[i].fi;
    }
    cout << -ans / 2<< endl;
    return 0;
}
/*
4
0 1 2 2
1 0 8 -3
2 8 0 5
2 -3 5 0
*/