n = int(input())
F = [list(map(int,input().split())) for _ in range(n)]
dp = [0] * (1 << n)

for bit in range(1 << n):
    if bin(bit).count('1') & 1:continue
    for i in range(n):
        if bit & (1 << i):continue
        b = bit | (1 <<i)
        for j in range(i+1,n):
            if bit & (1 << j):continue
            bj = b | (1 << j)
            if dp[bj] < dp[bit] + F[i][j]:
                dp[bj] = dp[bit] + F[i][j]
        break
print(dp[-1])