#include<bits/stdc++.h>
using namespace std;
#define int long long
#define bui __builtin_popcount
#define pii pair<int,int>
#define se second
#define fi first
#define mid (l+r>>1)
#define qwq cout<<"----------------------------------------------------------------------";
const int inf=1e18;
int read(){
	int x=0,f=1;char ch=getchar();
	while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
	while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}
	return x*f;
}
void prt(int x){
	if(x<0)putchar('-'),x=-x;
	if(x<10)putchar(x+'0');
	else prt(x/10),putchar(x%10+'0');
}
int ksm(int x,int y,int mod){
	if(y==0)return 1;
	int k=ksm(x,y/2ll,mod);
	if(y&1ll)return k*k%mod*x%mod;
	return k*k%mod;
}
const int N=1e6+5;
int gcd(int x,int y){return (y)?gcd(y,x%y):x;}
int max(int x,int y){return (x>y)?x:y;}
int min(int x,int y){return (x<y)?x:y;}
int n,cnt,a[25][25],f[(1<<24)],b[25];
void sl(){
	cin>>n;
	for(int i=0;i<n;i++){
		for(int j=0;j<n;j++)a[i][j]=read();
	}
	for(int i=3;i<(1<<n);i++){
		if(bui(i)&1)continue;
		cnt=0;
		for(int j=0;j<n;j++){
			if((1<<j)&i)b[++cnt]=j;
		}
		for(int j=2;j<=cnt;j++){
			f[i]=max(f[i-(1<<b[1])-(1<<b[j])]+a[b[1]][b[j]],f[i]);
		}
	}
	cout<<f[(1<<n)-1];
}
signed main(){
	int t=1;
//	cin>>t;
	while(t--)sl();
	return 0;
}