#include <iostream>
#include <vector>

int main() {
    int N;
    std::cin >> N;
    std::vector<std::vector<int>> F(N, std::vector<int>(N));
    for (int i = 0; i < N; i++) {
        for (int j = 0; j < N; j++) {
            std::cin >> F[i][j];
        }
    }
    std::vector<int> dp(1 << N, 0);
    for (int b = 0; b < (1 << N); b++) {
        if (__builtin_popcount(b) % 2 == 1) {
            continue;
        }
        for (int i = 0; i < N; i++) {
            if (b & (1 << i)) continue;
            for (int j = i + 1; j < N; j++) {
                if (b & (1 << j)) continue;
                int c = b | (1 << i) | (1 << j);
                dp[c] = std::max(dp[c], dp[b] + F[i][j]);
            }
        }
    }
    std::cout << dp[(1 << N) - 1] << std::endl;
}