#include<bits/stdc++.h>
using namespace std;
#define rep(i, n) for(int i = 0; i < (int)(n); i++)

int main(){
    int N;
    cin >> N;
    int F[N][N];
    rep(i, N) rep(j, N) cin >> F[i][j];
    unordered_map<int, int> dp;
    queue<int> que;
    que.push(0);
    while(!que.empty()){
        int c = que.front();
        que.pop();
        int j = 0;
        while((c & (1<<j))) j++;
        for(int k = j + 1; k < N; k++){
            if(c & (1<<k)) continue;
            int d = c + (1<<j) + (1<<k);
            if(dp[d] < dp[c] + F[j][k]){
                dp[d] = dp[c] + F[j][k];
                if(d != (1<<N) - 1) que.push(d);
            }
        }
    }
    cout << dp[(1<<N) - 1] << endl;
    return 0;
}