N = int(input())
f = [[int(j) for j in input().split()] for i in range(N)]
dp = [-1 for i in range(1 << N)]

dp[0] = 0

for i in range(1 << N):
	if dp[i] < 0:
		continue
	index = -1
	for j in range(N):
		if not i>>j&1:
			index = j
			break
	if index == -1:
		continue
	for k in range(N):
		if index == k or i>>k&1:
			continue
		dp[i | 1 << index | 1 << k] = max(dp[i | 1 << index | 1 << k],dp[i] + f[index][k])
print(dp[(1 << N) - 1])