#include <stdio.h>
#include <iostream>
#include <vector>
#include <queue>
#include <map>
#include <algorithm>

using ll = long long int;
const int INF = (1<<30);
const ll INFLL = (1ll<<60);
const ll MOD = (ll)(1e9+7);

#define l_ength size

void mul_mod(ll& a, ll b){
	a *= b;
	a %= MOD;
}

void add_mod(ll& a, ll b){
	a = (a<MOD)?a:(a-MOD);
	b = (b<MOD)?b:(b-MOD);
	a += b;
	a = (a<MOD)?a:(a-MOD);
}

std::map<int, ll> dp[15];
std::map<int, ll>::iterator itr;

ll f[25][25];

int main(void){
	int n,m,i,j,mask,l,r,t;
	ll tmp;
	std::cin >> n; m = n/2;
	for(i=0; i<n; ++i){
		for(j=0; j<n; ++j){
			std::cin >> f[i][j];
		}
	}
	dp[0][0] = 0ll;
	for(i=0; i<m; ++i){
		for(itr = dp[i].begin(); itr != dp[i].end(); ++itr){
			mask = (*itr).first;
			tmp = (*itr).second;
			for(j=0; j<n; ++j){
				if(!(mask&(1<<j))){
					l = j;
					for(r=j+1; r<n; ++r){
						if(mask&(1<<r)){
							continue;
						}
						t = mask+(1<<l)+(1<<r);
						if(dp[i+1].find(t) == dp[i+1].end()){
							dp[i+1][t] = tmp + f[l][r];
						}else{
							dp[i+1][t] = std::max(dp[i+1][t],tmp + f[l][r]);
						}
					}
					break;
				}
			}
		}
	}
	std::cout << dp[m][(1<<n)-1] << std::endl;
	return 0;
}