import sys

# sys.setrecursionlimit(200005)
int1 = lambda x: int(x)-1
p2D = lambda x: print(*x, sep="\n")
def II(): return int(sys.stdin.readline())
def LI(): return list(map(int, sys.stdin.readline().split()))
def LLI(rows_number): return [LI() for _ in range(rows_number)]
def LI1(): return list(map(int1, sys.stdin.readline().split()))
def LLI1(rows_number): return [LI1() for _ in range(rows_number)]
def SI(): return sys.stdin.readline().rstrip()
# dij = [(0, 1), (-1, 0), (0, -1), (1, 0)]
# dij = [(0, 1), (-1, 0), (0, -1), (1, 0), (1, 1), (1, -1), (-1, 1), (-1, -1)]
# inf = 18446744073709551615
inf = 4294967295
md = 10**9+7
# md = 998244353

n = II()
ff = LLI(n)

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

for s in range(1 << n):
    if dp[s] == -1: continue
    i = 0
    while s >> i & 1: i += 1
    for j in range(i+1, n):
        if s >> j & 1: continue
        ns = s | 1 << i | 1 << j
        dp[ns] = max(dp[ns], dp[s]+ff[i][j])

print(dp[-1])