def read_data():
    n = int(input())
    F = [list(map(int, input().split())) for _ in range(n)]
    return n, F

def solve(n, F):
    dp = [0] * (1 << n)
    for mask in range(1, 1 << n):
        bm = bin(mask)[2:]
        if bm.count('1') & 1:
            continue
        val = 0
        pos = [i for i in range(n) if mask & (1 << i)]
        for i in pos:
            for j in pos:
                if j >= i:
                    break
                pair = (1 << i) + (1 << j)
                val = max(val, dp[mask ^ pair] + F[i][j])
        dp[mask] = val
    return dp[-1]

n, F = read_data()
print(solve(n, F))