import sys
from collections import defaultdict
from itertools import combinations
sys.setrecursionlimit(10**7)
def I(): return int(sys.stdin.readline().rstrip())
def MI(): return map(int,sys.stdin.readline().rstrip().split())
def LI(): return list(map(int,sys.stdin.readline().rstrip().split()))
def LI2(): return list(map(int,sys.stdin.readline().rstrip()))
def S(): return sys.stdin.readline().rstrip()
def LS(): return list(sys.stdin.readline().rstrip().split())
def LS2(): return list(sys.stdin.readline().rstrip())


N = I()
F = [LI() for _ in range(N)]

dp = defaultdict(int)
for i in range(N//2):  # 出来ているペアの個数
    for A in list(combinations([i+j for j in range(N-i)],i)):
        flag = [0]*N
        state = (1<<i)-1
        for a in A:
            flag[a] = 1
            state += 1<<a
        for k in range(i,N):
            if flag[k] == 0:
                for l in range(k+1,N):
                    if flag[l] == 0:
                        new_state = state+(1<<k)+(1<<l)
                        dp[new_state] = max(dp[new_state],dp[state]+F[k][l])
                break

print(dp[(1<<N)-1])