# coding: utf-8
import array, bisect, collections, copy, heapq, itertools, math, random, re, string, sys, time
sys.setrecursionlimit(10 ** 7)
INF = 10 ** 20
MOD = 10 ** 9 + 7


def II(): return int(input())
def ILI(): return list(map(int, input().split()))
def IAI(LINE): return [ILI() for __ in range(LINE)]
def IDI(): return {key: value for key, value in ILI()}


def read():
    n = II()
    F = IAI(n)
    return (n, F)


def solve(n, F):
    dp = [-1] * (1 << n)
    dp[0] = 0

    for i in range(1 << n):
        if dp[i] < 0:
            continue
        for j in range(n):
            if i & (1 << j):
                continue
            for k in range(j + 1, n):
                if i & (1 << k):
                    continue
                t = i | (1 << j) | (1 << k)
                dp[t] = max(dp[t], dp[i] + F[j][k])
            break

    return dp[-1]


def main():
    params = read()
    print(solve(*params))


if __name__ == "__main__":
    main()