# 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):
    all_list = set()
    for i in range(1, n + 1):
        all_list.add(i)
    all_used = set()

    def find(set_used, set_left):
        if len(set_left) == 0:
            return 0

        now_ret = -1

        for i in itertools.combinations(list(set_left), 2):
            next_set_used = copy.copy(set_used)
            next_set_used.add(i[0])
            next_set_used.add(i[1])
            next_set_left = copy.copy(set_left)
            next_set_left.remove(i[0])
            next_set_left.remove(i[1])
            now_ret = max(now_ret, find(next_set_used, next_set_left) + F[i[0] - 1][i[1] - 1])

        return now_ret

    ans = find(all_used, all_list)
    return ans


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


if __name__ == "__main__":
    main()