/**
 *    author:  otera    
**/
#include<bits/stdc++.h>
using namespace std;

#define int long long
typedef long long ll;
typedef long double ld;
const int inf=1e9+7;
const ll INF=1LL<<60;
#define rep(i, n) for(int i = 0; i < n; ++ i)
#define per(i,n) for(int i=n-1;i>=0;i--)
#define Rep(i,sta,n) for(int i=sta;i<n;i++)
typedef pair<int, int> P;
typedef pair<ll, ll> LP;
#define fr first
#define sc second
#define all(c) c.begin(),c.end()
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }

void solve() {
    int n; cin >> n;
    vector<vector<int>> f(n, vector<int>(n));
    rep(i, n) {
        rep(j, n) {
            cin >> f[i][j];
        }
    }
    unordered_map<int, int> dp;
    auto rec = [&](auto&& self, int bit) -> int {
        if(bit == 0) return 0;
        if(dp.count(bit)) return dp[bit];
        int j = -1;
        rep(i, n) {
            if(bit & (1<<i)) {
                j = i;
                break;
            }
        }
        int res = 0;
        for(int i = j + 1; i < n; ++ i) {
            if(bit & (1<<i)) {
                int nbit = bit - (1<<j) - (1<<i);
                chmax(res, self(self, nbit) + f[j][i]);
            }
        }
        return dp[bit] = res;
    };
    cout << rec(rec, (1<<n) - 1) << "\n";
}

signed main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	//cout << fixed << setprecision(20);
	//int t; cin >> t; rep(i, t)solve();
	solve();
    return 0;
}