def generate_pairings(n, yield_func):
    assert n > 0 and n % 2 == 0

    def rec(p, t, g):
        if p == n:
            pairs = []
            partners = [-1] * m
            for i in range(n):
                gid = g[i]
                if partners[gid] == -1:
                    partners[gid] = i
                else:
                    pairs.append((partners[gid], i))

            yield_func(pairs)
            return

        for i in range(m):
            x = t[i]
            if x == 2: continue
            t[i] += 1
            g[p] = i
            rec(p+1, t, g)
            t[i] -= 1
            if x == 0: break

    m = n // 2
    t = [0] * m  # 各グループの占領人数
    g = [0] * n  # t[i] : i 番目の人のグループ番号
    rec(0, t, g)


N = int(input())
F = []
for _ in range(N):
    F.append(list(map(int, input().split())))


def bsf(x: int) -> int:
    return (x & -x).bit_length() - 1


dp = [-1] * (1 << N)
dp[0] = 0
for i in range(1 << N):
    if dp[i] == -1: continue
    pi = bsf(~i)
    for pj in range(pi+1, N):
        if not (i & (1 << pj)):
            key = i | (1 << pi) | (1 << pj)
            dp[key] = max(dp[key], dp[i] + F[pi][pj])

ans = dp[(1 << N) - 1]
print(ans)