#include<cstdio>
#include<vector>
#include<queue>


using namespace std;

using vi=vector<int>;
using vvi=vector<vi>;


int max_u(int&m, int v)
{
	if(m<v)
	{
		m=v;
		return 1;
	}
	return 0;
}


void solve_i(vvi& f, vi& score, int rest)
{
	int i, j, n=f.size(), nrest;

	if(rest==0) return;
	if(score[rest]>=0) return;

	for(i=0;i<n;i++)
	{
		if(rest&(1<<i)) break;
	}

	for(j=i+1;j<n;j++)
	{
		if(rest&(1<<j))
		{
			nrest=rest^(1<<i)^(1<<j);
			solve_i(f, score, nrest);
			max_u(score[rest], f[i][j]+score[nrest]);
		}
	}
	return;
}


int solve(vvi& f)
{
	int n=f.size();
	vi score(1<<n, -1);
	int rest=(1<<n)-1;

	score[0]=0;
	solve_i(f, score, rest);

	return score[(1<<n)-1];
}


int main(void)
{
	vvi f;
	int n;

	while(scanf("%d", &n)==1)
	{
		f.resize(n);
		for(int i=0;i<n;i++)
		{
			f[i].resize(n);
			for(int j=0;j<n;j++) scanf("%d", &f[i][j]);
		}
		printf("%d\n", solve(f));
	}

	return 0;
}