n = int(input())
f = [list(map(int, input().split())) for i in range(n)]
dp = [-1] * (1 << n)
dp[0] = 0
for i in range(1 << n):
    if dp[i] == -1:
        continue
    for j in range(n):
        if i & (1 << j):
            continue
        for k in range(j, n):
            if i & (1 << k):
                continue
            to = i | (1 << j) | (1 << k)
            dp[to] = max(dp[to], dp[i] + f[j][k])
print(dp[(1 << n) - 1])