def solve():
    n = int(input())
    A = []

    for i in range(n):
        A.append(list(map(int, input().split())))

    dp = [-1] * (1 << n)
    dp[0] = 0

    for i in range(1 << n):
        if dp[i] < 0:
            continue
        for j in range(n):
            if i & (1 << j):
                continue
            for k in range(j + 1, n):
                if i & (1 << k):
                    continue
                t = i | (1 << j) | (1 << k)
                dp[t] = max(dp[t], dp[i] + A[j][k])

    return dp[-1]


print(solve())