import bisect
import copy
import decimal
import fractions
import heapq
import itertools
import math
import random
import sys
from collections import Counter,deque,defaultdict
from functools import lru_cache,reduce
from heapq import heappush,heappop,heapify,heappushpop,_heappop_max,_heapify_max
def _heappush_max(heap,item):
    heap.append(item)
    heapq._siftdown_max(heap, 0, len(heap)-1)
def _heappushpop_max(heap, item):
    if heap and item < heap[0]:
        item, heap[0] = heap[0], item
        heapq._siftup_max(heap, 0)
    return item
from math import gcd as GCD
read=sys.stdin.read
readline=sys.stdin.readline
readlines=sys.stdin.readlines
from typing import NamedTuple, Optional, List, cast

N=int(readline())
F=[list(map(int,readline().split())) for i in range(N)]
dp=[0]*(1<<N)
for bit in range(1<<N):
    lst=[i for i in range(N) if bit>>i&1]
    if len(lst)%2:
        continue
    if lst:
        x=lst[0]
        for y in lst:
            dp[bit]=max(dp[bit],dp[bit^1<<x^1<<y]+F[x][y])
ans=dp[-1]
print(ans)