N = int(input())
f = [[int(j) for j in input().split()] for i in range(N)]
dp = [0 for i in range(1 << N)]
for i in range(1 << N):
	bit = 0
	for j in range(N):
		if (i>>j)&1:
			bit+=1
	if bit&1:
		continue
	for j in range(N):
		if (i >> j)&1:
			continue
		for k in range(N):
			if j == k:
				continue
			if (i>>k) & 1:
				continue
			dp[i | 1 << j | 1 << k] = max(dp[i | 1 << j | 1 << k],dp[i]+f[j][k])
print(dp[(1<<N)-1])