#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define FASTIO
#define endl "\n"  // Since endl forces a buffer flush which slows down large I/O operations.
#define ff first
#define ss second
#define pb push_back
#define input(c, n) for (int i = 0; i < n; ++i) cin >> c[i];
#define exit_message(s) return 0 * printf(s)
#define show_all(c) for (auto i: c) cout << i << " "; cout << "\n";
#define display(c, a, n) cout << "Displaying array \"" << #c << "\" : \n"; for (int (i) = (a); (i) < (n); ++(i)) cout << (c)[(i)] << " "; cout << "\n";
#define forl(i, a, n) for (int i = (a); (i) < (n); ++(i))
#define dugbe(k) cout << "-\t> " << #k << " : " << k << "\n";
#define dugbev(vec, idx) cout << "-\t> " << #vec << "[" << idx << "] : " << vec[idx] << "\n";

// What follows is a magical ordered set data structure.
// Supports the following functions:
// find_by_order(int k) - returns k'th smallest element (0-indexed)
// order_of_key(int k) - returns number of elements strictly smaller than k.

// using namespace __gnu_pbds;
// #define ordered_set tree <ll, null_type, greater_equal <ll>, rb_tree_tag, tree_order_statistics_node_update>

/* TIPS FOR DEBUGGING
 * Check if values are not overflowing (use long long where required)
 * Check if ranges are inclusive or not.
 * Check properly if greedy will work or not before using it.
 * Check EDGE CASES!! Seriously, even in 2B, saving 8 points by being
 * 2 minutes faster will bite you in the ass if you don't make sure
 * it works on edge cases.
 * Keep adding to this list.
*/

using namespace std;
typedef long long ll;
typedef pair<int, int> pr;
typedef pair<ll, ll> prll;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<pr> vpr;
ifstream in("input.txt");
const ll mod = 1e9 + 7;
const long double eps = 1e-7;

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

long long true_rand(long long n)
{
	// Returns a random number between 0 and n - 1 inclusive using mt19937.
    uniform_int_distribution<long long> uid(0, n - 1);
    return uid(rng);
}

ll mod_pow(ll a, ll b)
{
	if (b == 0)
		return 1LL;

	ll res = mod_pow(a, b >> 1);
	res = (res * res) % mod;
	if (b & 1LL)
		res = (res * a) % mod;
	
	return res;
}

const int N = 50 + 5, INF = 1e9 + 100;

void add_self(int &a, int b)
{
	a += b;
	a %= mod;
}

int32_t main()
{
	#ifdef FASTIO
		ios_base::sync_with_stdio(false);
		cin.tie(NULL);
	#endif
	// freopen("input.txt", "r", stdin);
	// freopen("output.txt", "w", stdout);

	int n;
	cin >> n;
	vector<vi> g(n, vi(n, 0));
	forl(i, 0, n)
	{
		forl(j, 0, n)
		{
			cin >> g[i][j];
		}
	}
	int lim = 1 << n;
	int mask = 0;

	vector<ll> comp(lim);
	for (mask = 0; mask < lim; ++mask)
	{
		for (int i = 0; i < n; ++i)
		{
			if (mask & (1 << i))
			{
				for (int j = i + 1; j < n; ++j)
				{
					if (mask & (1 << j))
						comp[mask] += g[i][j];
				}
			}
		}
		// dugbev(comp, mask);
	}

	vector<ll> dp(lim);
	// 1's in mask will represent free rabbits.
	for (mask = lim - 1; mask >= 0; --mask)
	{
		// Iterate over submasks.

		// dugbe(mask);
		int alt_mask = mask;

		for (int i = n - 1; i >= 0; --i)
		{
			if (alt_mask & (1 << i))
			{
				alt_mask ^= (1 << i);
				break;
			}
		}
		int temp = alt_mask;
		for (; temp > 0; temp = (temp - 1) & alt_mask)
		{
			dp[temp] = max(dp[temp], dp[mask] + comp[temp ^ mask]);
			// dugbe(temp << " " << dp[temp]);
		}
		dp[0] = max(dp[0], dp[mask] + comp[mask]);
		// dugbe(dp[0]);
	}
	cout << dp[0]  << "\n";

	return 0;
}

Measured memory_bytes: 1280