#include<bits/stdc++.h>
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp>
#include<ext/rope>
using namespace std;
using namespace chrono;
using namespace __gnu_pbds;
using namespace __gnu_cxx;
mt19937 rng(high_resolution_clock::now().time_since_epoch().count());
mt19937_64 rngll(high_resolution_clock::now().time_since_epoch().count());
template<typename T> T ctmax(T &x, const T &y){ return x = max(x, y); }
template<typename T> T ctmin(T &x, const T &y){ return x = min(x, y); }
template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;



int main(){
	cin.tie(0)->sync_with_stdio(0);
	int n;
	cin >> n;
	vector<vector<int>> a(n, vector<int>(n));
	for(auto i = 0; i < n; ++ i){
		for(auto j = 0; j < n; ++ j){
			cin >> a[i][j];
		}
	}
	const long long minf = numeric_limits<long long>::min() / 8;
	const int mx = 1 << n;
	vector<long long> dp(mx, minf), sum(mx);
	dp[0] = 0;
	for(auto mask = 1; mask < mx; ++ mask){
		for(auto i = 0; i < n; ++ i){
			if(mask & 1 << i){
				for(auto j = i + 1; j < n; ++ j){
					if(mask & 1 << j){
						sum[mask] += a[i][j];
					}
				}
			}
		}
		for(auto submask = mask; submask; submask = (submask - 1) & mask){
			ctmax(dp[mask], dp[mask ^ submask] + sum[submask]);
		}
	}
	cout << dp.back();
	return 0;
}

/*

*/

////////////////////////////////////////////////////////////////////////////////////////
//                                                                                    //
//                                   Coded by Aeren                                   //
//                                                                                    //
////////////////////////////////////////////////////////////////////////////////////////
#include <bits/stdc++.h>
using namespace std;
#define rep(i, n)  for(long long i=0;i<(long long)(n);i++)
#define REP(i,k,n) for(long long i=k;i<(long long)(n);i++)
#define all(a) a.begin(),a.end()
#define pb emplace_back
#define eb emplace_back
#define lb(v,k) (lower_bound(all(v),k)-v.begin())
#define ub(v,k) (upper_bound(all(v),k)-v.begin())
#define fi first
#define se second
#define pi M_PI
#define PQ(T) priority_queue<T>
#define SPQ(T) priority_queue<T,vector<T>,greater<T>>
#define dame(a) {out(a);return 0;}
#define decimal cout<<fixed<<setprecision(15);
#define dupli(a) a.erase(unique(all(a)),a.end())
typedef long long ll;
typedef pair<ll,ll> P;
typedef tuple<ll,ll,ll> PP;
typedef tuple<ll,ll,ll,ll> PPP;
typedef multiset<ll> S;
using vi=vector<ll>;
using vvi=vector<vi>;
using vvvi=vector<vvi>;
using vvvvi=vector<vvvi>;
using vp=vector<P>;
using vvp=vector<vp>;
using vb=vector<bool>;
using vvb=vector<vb>;
const ll inf=1001001001001001001;
const ll INF=1001001001;
const ll mod=1000000007;
const double eps=1e-10;
template<class T> bool chmin(T&a,T b){if(a>b){a=b;return true;}return false;}
template<class T> bool chmax(T&a,T b){if(a<b){a=b;return true;}return false;}
template<class T> void out(T a){cout<<a<<'\n';}
template<class T> void outp(T a){cout<<'('<<a.fi<<','<<a.se<<')'<<'\n';}
template<class T> void outvp(T v){rep(i,v.size())cout<<'('<<v[i].fi<<','<<v[i].se<<')';cout<<'\n';}
template<class T> void outvvp(T v){rep(i,v.size())outvp(v[i]);}
template<class T> void outv(T v){rep(i,v.size()){if(i)cout<<' ';cout<<v[i];}cout<<'\n';}
template<class T> void outvv(T v){rep(i,v.size())outv(v[i]);}
template<class T> bool isin(T x,T l,T r){return (l)<=(x)&&(x)<=(r);}
template<class T> void yesno(T b){if(b)out("yes");else out("no");}
template<class T> void YesNo(T b){if(b)out("Yes");else out("No");}
template<class T> void YESNO(T b){if(b)out("YES");else out("NO");}
template<class T> void noyes(T b){if(b)out("no");else out("yes");}
template<class T> void NoYes(T b){if(b)out("No");else out("Yes");}
template<class T> void NOYES(T b){if(b)out("NO");else out("YES");}
void outs(ll a,ll b){if(a>=inf-100)out(b);else out(a);}
ll gcd(ll a,ll b){if(b==0)return a;return gcd(b,a%b);}
ll modpow(ll a,ll b){ll res=1;a%=mod;while(b){if(b&1)res=res*a%mod;a=a*a%mod;b>>=1;}return res;}

int main(){
    ll n;cin>>n;
    vvi v(n,vi(n));
    rep(i,n)rep(j,n)cin>>v[i][j];
    vi dp(1<<n);
    vi val(1<<n);
    rep(i,1<<n)rep(j,n)REP(k,j+1,n)if((i>>j&1)&&(i>>k&1))val[i]+=v[j][k];
    dp[0]=0;
    REP(i,1,1<<n){
        for(int j=i;j>=0;j=(j-1)&i){
            chmax(dp[i],dp[j]+val[i&(~j)]);
            if(j==0)break;
        }
    }
    out(dp[(1<<n)-1]);
}