from collections import *
from itertools import *
from functools import *
from heapq import *
import sys,math
input = sys.stdin.readline

N = int(input())
F = [list(map(int,input().split())) for _ in range(N)]
INF = (1<<60)
dp = [-INF]*(1<<N)
dp[0] = 0
for i in range(1<<N):
    
    if bin(i).count('1')%2:
        continue
    
    T = []
    for j in range(N):
        if (i>>j)&1:
            continue
        T.append(j)
    
    n = len(T)
    for j in range(n-1):
        tj = T[j]
        jj = (1<<tj)
        for k in range(j+1,n):
            tk = T[k]
            kk = (1<<tk)
            dp[i|jj|kk] = max(dp[i|jj|kk],dp[i] + F[tj][tk])
# print(dp)         
print(dp[-1])