n = int(input())
d = [list(map(int,input().split())) for _ in range(n)]
N = 1<<n
INF = 1<<30
dp = {0:0}
from collections import deque
q = deque([0])
while q:
    mask = q.popleft()
    v = (~mask&-(~mask)).bit_length() - 1
    for w in range(v+1,n):
        if mask>>w&1: continue
        nmask = mask | ((1<<w)+(1<<v))
        if nmask in dp:
            dp[nmask] = max(dp[nmask], dp[mask] + d[v][w])
        else:
            dp[nmask] = dp[mask] + d[v][w]
            q.append(nmask)
print(dp[N-1])