#include <bits/stdc++.h>

using namespace std;

#define PB	push_back
#define ALL(x)	(x).begin(), (x).end()
#define ALLR(x)	(x).rbegin(), (x).rend()
#define MP	make_pair

#define debug(args...) { string _s = #args; replace(ALL(_s), ',', ' '); stringstream ss(_s); cerr << endl;_debug(ss, args); }
#define _rg auto it = next(v.begin()); it != v.end(); it++
#define _input ostream& operator <<(ostream& out

template<typename T, typename U>
_input, const pair<T, U>& p) {
	out << "(" << p.first << ", " << p.second << ")";
	return out;
}

#define cont(c) template<typename T> _input, const c<T>& v) { \
					if (v.empty()) return out; \
					out << "[" << *v.begin(); \
					for (_rg) out << ", " << *it; \
					out << "]"; return out; \
				}
				
#define cont2(c) template<typename T, typename U> _input, const c<T, U>& v) { \
					if (v.empty()) return out; \
					out << "[" << *v.begin(); \
					for (_rg) out << ", " << *it; \
					out << "]"; return out; \
				}

cont(vector) cont(set) cont(multiset) cont(queue) cont2(map)

template<typename T, size_t n, typename= enable_if_t<!is_same<T, char>::value>>
_input, const T(&v)[n]) {
	if (n == 0) return out;
	out << "[" << v[0];
	for (int i = 1; i < (int)n; i++) out << ", " << v[i];
	out  << "]"; return out;
}

template<typename T, typename... Ts>
void _debug(stringstream& ss, const T &arg) {
	string name; ss >> name;
	cerr << name << " = " << arg << endl;
}

template<typename T, typename... Ts>
void _debug(stringstream& ss, const T& arg, const Ts&... args) {
	string name; ss >> name; 
	cerr << name << " = " << arg << ", ";
	if (is_class<T>::value || is_array<T>::value) cerr << endl;
	_debug(ss, args...);
}

#define FAST_IO ios::sync_with_stdio(false); cin.tie(0)

#define int long long int

typedef pair<int, int> ii;
typedef pair<pair<int, int>, int> iii;
typedef vector<int> vi;
typedef vector<iii> viii;
typedef vector<vi> vvi;
typedef vector<ii> vii;
typedef vector<string> vs;
typedef vector<bool> vb;
typedef unsigned long long ull;

const int INF = LONG_LONG_MAX>>1;
const int NINF = LONG_LONG_MIN/2;
const double PI = 3.141592653589793238;

vi pre;
// pre[mask] - score of group which mask represent;
vi dp;
// dp[mask] - best total score if we grouped rabbits from 'mask' already

void rec(int i, vi& not_taken, int score, int mask, int group) {
	if (i == (int)not_taken.size()) {
		dp[mask] = max(dp[mask], score + pre[group]);
		return;
	}
	
	rec(i+1, not_taken, score, mask, group);
	rec(i+1, not_taken, score, mask^(1<<not_taken[i]),
		group^(1<<not_taken[i]));
	
}

int32_t main() {
	FAST_IO;
	
	int n;
	cin >> n;
	vvi a(n, vi(n));
	
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < n; j++) {
			cin >> a[i][j];
		}
	}
	
	//O(2^n * n^2);
	pre.resize(1<<n);
	for (int mask = 0; mask < (1<<n); mask++) {
		for (int i = 0; i < n; i++) {
			if (mask & (1 << i)) {
				for (int j = i+1; j < n; j++) {
					if (mask & (1 << j)) {
						pre[mask] += a[i][j];
					}
				}
			}
		}
	}
	
	dp.resize((1<<n), -INF);
	dp[0] = 0;
	// O(2^n * n + 3^n);
	for (int mask = 0; mask < (1<<n); mask++) {
		vi not_taken;
		for (int i = 0; i < n; i++) {
			if (!(mask & (1 << i))) {
				not_taken.PB(i);
			}
		}
		rec(0, not_taken, dp[mask], mask, 0);
	}
	
	cout << dp[(1<<n)-1] << endl;
}

// g++ -Wall -Wextra -Wshadow -fsanitize=undefined -std=c++17


Measured memory_bytes: 1280