#include <iostream>
#include <algorithm>
#include <string>
#include <vector>

using namespace std;

void updmax(int &x, int y) {
	x = std::max(x, y);
}

int main() {
	int n;
	std::cin >> n;
	std::vector<std::vector<int>> cost(n, std::vector<int>(n));
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < n; j++) {
			std::cin >> cost[i][j];
		}
	}
	
	constexpr int INF = 1e9;
	std::vector<int> dp(1 << n, -INF);
	dp[0] = 0;

	std::vector<bool> ok(1 << n);
	ok[0] = true;
	for (int i = 1; i < 1 << n; i++) {
		ok[i] = !ok[i & i - 1];
	}

	for (int i = 0; i < 1 << n; i++) {
		if (!ok[i]) {
			continue;
		}
		int j;
		for (j = 0; j < n; j++) {
			if (~i >> j & 1) {
				break;
			}
		}
		for (int k = j + 1; k < n; k++) {
			if (i >> k & 1) {
				continue;
			}
			updmax(dp[i | 1 << j | 1 << k], dp[i] + cost[j][k]);
		}
	}
	std::cout << dp[(1 << n) - 1] << std::endl;
}