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


using namespace std;

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


struct que_t
{
	int used_f, used_n, score;
	bool operator<(const que_t& rhs) const
	{
		if(used_n>rhs.used_n) return 1;
		return 0;
	}
};


priority_queue<que_t> que;


void push(que_t& q)
{
	que.push(q);
}


int pop(que_t& q)
{
	if(que.empty()) return 0;
	q=que.top();
	que.pop();
	return 1;
}


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


int solve(vvi& f)
{
	int n=f.size();
	vi score(1<<n, -1);
	int f_i, f_j, i, j;
	que_t q;


	q.used_f=0;
	q.used_n=0;
	q.score=0;
	push(q);
	while(pop(q))
	{
		if(!max_u(score[q.used_f], q.score)) continue;
		for(i=0;i<n;i++)
		{
			f_i=(1<<i);
			if(q.used_f&f_i) continue;
			q.used_f|=f_i;
			for(j=i+1;j<n;j++)
			{
				f_j=(1<<j);
				if(q.used_f&f_j) continue;
				q.used_f|=f_j;
				q.used_n+=2;
				q.score+=f[i][j];
				push(q);
				q.score-=f[i][j];
				q.used_n-=2;
				q.used_f&=~f_j;
			}
			q.used_f&=~f_i;
		}
	}


	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;
}