// **** WHEN THE GOING GETS TOUGH, THE TOUGH GETS GOING. ****

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
using namespace std;
#define ll long long int
#define ull unsigned long long int
#define ld long double
#define ordered_set tree < ll ,  null_type ,  less<ll> ,  rb_tree_tag ,  tree_order_statistics_node_update >
//added two more functions to set
//(1)*(set.find_by_order(k))[kth element in the sorted set] 
//(2)set.order_of_key(k)[count of elements strictly less than k]

typedef vector< int > vi;
typedef vector< ll > lvi;
typedef vector< vi > vvi;
typedef vector< lvi > lvvi;
typedef pair< int,int > ii;
typedef pair< ll,ll > lii;
typedef vector<ii> vii;
typedef vector<lii> lvii;

#define min_prq(t) priority_queue<t,vector<t>,greater<t>>
#define max_prq(t) priority_queue<t>
#define pb push_back
#define all(c) (c).begin(),(c).end()
#define tr(c,i) for(auto i = (c).begin(); i != (c).end(); i++)//remember i is an iterator
#define present(c,x) ((c).find(x) != (c).end())//for sets,maps,multimaps
#define cpresent(c,x) (find(all(c),x) != (c).end())//for vectors
#define tc(t) int (t); cin>>(t);while((t)--)
#define ff first
#define ss second
#define error(args...) { string _s = #args; replace(_s.begin(), _s.end(), ',', ' '); stringstream _ss(_s); istream_iterator<string> _it(_ss); err(_it, args); }
void err(istream_iterator<string> it) {}
template<typename T, typename... Args>
void err(istream_iterator<string> it, T a, Args... args) {
	cerr << *it << " is " << a << endl;
	err(++it, args...);
}

//-----------------------------------------------------------------------------------------------------------------------------------------------------------------
#define mod 1000000007
//-----------------------------------------------------------------------------------------------------------------------------------------------------------------

ll mod_sum() { return 0LL; }
template<typename T, typename... Args>
T mod_sum(T a, Args... args) { return ((a + mod_sum(args...))%mod + mod)%mod; }

ll mod_product() { return 1LL; }
template<typename T, typename... Args>
T mod_product(T a, Args... args) { return (a*mod_product(args...))%mod; }
//-----------------------------------------------------------------------------------------------------------------------------------------------------------------


signed main()
{
	ios_base::sync_with_stdio(false);
    cin.tie(NULL);	
    ll n;
    cin>>n;
    lvvi adj;
    adj.resize(n+2,lvi(n+2));
    for (int i = 0; i < n; ++i)
    {
    	for (int j = 0; j < n; ++j)
    	{
    		cin>>adj[i][j];
    	}
    }
    lvi pre((1<<n),0);
    for(ll mask=0;mask<(1<<n);mask++)
    {
    	for(int i=0;i<n;i++)
    	{
    		if((1<<i)&mask)
    		{
    			for(int j=i+1;j<n;j++)
    			{
    				if((1<<j)&mask)
    				{
    					pre[mask]+=adj[i][j];
    				}
    			}
    		}
    	}
    }
	lvi dp(1<<n,-1e18 + 10);
	dp[0]=0;
	for(ll mask=0;mask<(1<<n);mask++)
	{
		ll not_taken=0;
		for(int j=0;j<n;j++)
		{
			if(!(mask&(1<<j))) not_taken|=(1<<j);
		}
		for(ll s=not_taken;s>0;s=(s-1)&(not_taken))
		{
			dp[mask^s]=max(dp[mask^s],pre[s]+dp[mask]);
		}
	}
	cout<<dp[(1<<n)-1]<<endl;
	return 0;
}

Measured memory_bytes: 1280