n = int(input())
F = [list(map(int, input().split())) for _ in range(n)]
dp = [0] * (1 << n)
for bit in range((1 << n) - 1):
    pc = 0
    lst = []
    for i in range(n):
        if bit >> i & 1:
            continue
        lst.append(i)
        pc += 1
    if pc & 1:
        continue
    i = lst[0]
    for j in lst[1:]:
        dbit = (1 << i) | (1 << j)
        nbit = bit | dbit
        dp[nbit] = max(dp[nbit], dp[bit] + F[i][j])
print(dp[-1])