#include <bits/stdc++.h>
#define int long long
//#define USE_FREOPEN
//#define MUL_TEST
#define FILENAME "group"
using namespace std;
constexpr int MAXN = 24;
int dp[(1 << MAXN) + 5],f[MAXN + 5][MAXN + 5];

void solve() {
	int n;
	cin >> n;
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < n; j++) {
			cin >> f[i][j];
		}
	}
	memset(dp,-0x3f,sizeof(dp));
	dp[0] = 0;
	for (int s = 0; s < (1 << n); s++) {
		if (dp[s] == -1) break;
		for (int i = 0; i < n; i++)
			if (((s >> i) & 1) == 0) {
				for (int j = 0; j < n; j++) {
					if (((s >> j) & 1) == 0) {
						int nxt = s ^ (1 << i) ^ (1 << j);
						dp[nxt] = max(dp[nxt],dp[s] + f[i][j]);
					}
				}
			}
	}
	cout << dp[(1 << n) - 1] << '\n';
}

signed main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr); cout.tie(nullptr);

	#ifdef USE_FREOPEN
		freopen(FILENAME ".in","r",stdin);
		freopen(FILENAME ".out","w",stdout);
	#endif
	int _ = 1;
	#ifdef MUL_TEST
		cin >> _;
	#endif
	while (_--)
		solve();
	_^=_;
	return 0^_^0;
}