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

#define REP(i,n) for(int i=0;i<(int)n;++i)
#define FOR(i,c) for(__typeof((c).begin())i=(c).begin();i!=(c).end();++i)
#define ALL(c) (c).begin(), (c).end()
typedef int Weight;
const int N = 50;
const int INF = 1 << 25;

Weight adj[N][N];
int sz, sorted[N][N], num[N];
int match[N];

void rec(int match[], int p, int l, Weight w, Weight &opt) {
	int q = p + 1, i;
	//	if(w >= opt) return;
	for(; q < sz; ++q) if(match[q] == -1) break;
	int m = num[q], *list = sorted[q];
	REP(j, m) if(match[i = list[j]] == -1) { // process greedily
		match[q] = i, match[i] = q;
		w += adj[i][q];
		if(l + 1 < sz / 2) rec(match, q, l + 1, w, opt);
		else opt = min(opt, w);
		w -= adj[i][q];
		match[q] = -1, match[i] = -1;
	}
}
int gs;
bool compareWith(int i, int j) { return adj[gs][i] < adj[gs][j]; }
Weight minimumWeightMatching() {
	for(gs = 0; gs < sz; ++gs) { // sort adjacent nodes by edge weight
		for(int j = gs + 1; j < sz; ++j)
			sorted[gs][num[gs]++] = j;
		sort(sorted[gs], sorted[gs] + num[gs], compareWith);
	}
	fill(match, match + sz, -1);
	Weight opt = INF;
	rec(match, -1, 0, 0, opt);
	return opt;
}

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

	cin >> sz;
	for(int i = 0; i < sz; i++) {
		for(int j = 0; j < sz; j++) {
			cin >> adj[i][j];
			adj[i][j] *= -1;
			if(i == j) adj[i][j] = INF;
		}
	}

	cout << -minimumWeightMatching() << endl;
}