#!/usr/bin/ python3.8
import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines
from functools import lru_cache

N = int(readline())
F = tuple(tuple(map(int, line.split())) for line in readlines())


@lru_cache(None)
def f(S):
    if not S:
        return 0
    i = (S & (-S)).bit_length() - 1
    ret = 0
    for j in range(i + 1, N):
        if not S & (1 << j):
            continue
        T = S - (1 << i) - (1 << j)
        x = f(T) + F[i][j]
        if ret < x:
            ret = x
    return ret


full = (1 << N) - 1
print(f(full))