#include<bits/stdc++.h>
using namespace std;
int n,a[44][44],dp[1<<24];
signed main(){
cin>>n;
for(int i=1;i<=n;i++){
	for(int j=1;j<=n;j++)cin>>a[i][j];
}
for(int i=0;i<(1<<n);i++){
	if(__builtin_popcount(i)%2)continue;
	for(int j=0;j<n;j++){
		if(!((i>>j)&1))continue;
		for(int k=0;k<n;k++){
			if(j==k||(!((i>>k)&1)))continue;
			dp[i]=max(dp[i],dp[i^(1<<k)^(1<<j)]+a[j+1][k+1]);
		}
	}
}
cout<<dp[(1<<n)-1];
	return 0;
}