n = int(input())
F = [list(map(int,input().split())) for _ in range(n)]
dp = [1] * (1 << n)
dp[0] = 0
for bit in range(1 << n):
    if dp[bit] < 0:continue
    i = 0
    while bit >> i & 1:i += 1
    b = bit | (1 <<i)
    for j in range(i+1,n):
        if bit >> j & 1:continue
        bj = b | (1 << j)
        if dp[bj] < dp[bit] + F[i][j]:
            dp[bj] = dp[bit] + F[i][j]
print(dp[-1])