#include<stdio.h>
#include<stdlib.h>

#define POS(i,j) ((i)*n+(j))
#define MAX(a,b) ((a)>(b)?(a):(b))

int calc(int bit,int n,int *f,int *dp){
  if(dp[bit]!=-1) return dp[bit];

  int res=0;
  int i,j;
  for(i=0;i<n;i++){
    if((bit>>i)&0x01){
      for(j=i+1;j<n;j++){
	if((bit>>j)&0x01){
	  res=MAX(res,f[POS(i,j)]+calc(bit^(1<<i)^(1<<j),n,f,dp));
	}
      }
    }
  }
  dp[bit]=res;
  return res;
}

void run(void){
  int n;
  scanf("%d",&n);

  int *f=(int *)malloc(sizeof(int)*n*n);
  int i,j;
  for(i=0;i<n;i++){
    for(j=0;j<n;j++){
      scanf("%d",f+POS(i,j));
    }
  }

  int *dp=(int *)malloc(sizeof(int)*(1<<n));
  for(i=0;i<(1<<n);i++){
    dp[i]=-1;
  }
  dp[0]=0;
  int ans=calc((1<<n)-1,n,f,dp);
  printf("%d\n",ans);
  free(f);
  free(dp);
  return;
}

int main(void){
  run();
  return 0;
}