#include<bits/stdc++.h>
#define inf 0x3f3f3f3f3f3f3f3f
#define N 30
#define M 20000007
using namespace std;
int v[N][N],n,f[M];
signed main()
{
    scanf("%d",&n);
    for(int i=1;i<=n;i++)
        for(int j=1;j<=n;j++)
            scanf("%d",&v[i][j]);
    memset(f,-0x3f,sizeof(f));
    f[0]=0;
    for(int i=0;i<(1<<n);i++)
    {
        if(f[i]==-inf)continue;
        int id=0;
        for(int j=1;j<=n;j++)
        {
            if(!(i&(1<<(j-1))))
            {
                if(id==0)id=j;
                else f[i|(1<<(id-1))|(1<<(j-1))]=max(f[i|(1<<(id-1))|(1<<(j-1))],f[i]+v[id][j]);
            }
        }
    }
    printf("%d ",f[(1<<n)-1]);
    return 0;
}