#include <bits/stdc++.h>

#define FOR(i, a, b) for (ll i = (a); i < (b); i++)
#define RFOR(i, a, b) for (ll i = (b)-1; i >= (a); i--)
#define rep(i, n) for (ll i = 0; i < (n); i++)
#define rep1(i, n) for (ll i = 1; i <= (n); i++)
#define rrep(i, n) for (ll i = (n)-1; i >= 0; i--)

#define pb push_back
#define mp make_pair
#define fst first
#define snd second
#define show(x) cout << #x << " = " << x << endl
#define chmin(x, y) x = min(x, y)
#define chmax(x, y) x = max(x, y)
#define pii pair<int, int>
#define vi vector<int>

using namespace std;
template <class S, class T>
ostream& operator<<(ostream& o, const pair<S, T>& p)
{
    return o << "(" << p.first << "," << p.second << ")";
}
template <class T>
ostream& operator<<(ostream& o, const vector<T>& vc)
{
    o << "sz = " << vc.size() << endl
      << "[";
    for (const T& v : vc)
        o << v << ",";
    o << "]";
    return o;
}
using ll = long long;
constexpr ll MOD = 1000000007;
constexpr ll MAX = (1LL << 24);
ll dp[MAX];

int main()
{
    int n;
    cin >> n;
    vector<vector<int>> score(n, vector<int>(n));
    rep(i, n)
    {
        rep(j, n)
        {
            cin >> score[i][j];
        }
    }

    const ll maximum = (1LL << n);

    dp[0] = 0;
    rep1(m, maximum - 1)
    {
        int top = -1;
        rrep(i, n)
        {
            if (top == -1 and ((m >> i) & 1) == 1) {
                top = i;
                continue;
            }
            if (((m >> i) & 1) == 1) {
                const ll mask = (1LL << top) + (1LL << i);
                dp[m] = max(dp[m], dp[m - mask] + score[top][i]);
            }
        }
    }
    cout << dp[maximum - 1] << endl;
    return 0;
}