# 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):
    n_div = n // 2
    l_combination_a = [c for c in itertools.permutations(range(1, n), n_div)]
    l_combination_b = [c for c in itertools.permutations(range(0, n - 1), n_div)]
    ans = 0
    for a in l_combination_a:
        for b in l_combination_b:
            tmp_ans = 0
            for i_a, i_b in zip(a, b):
                if i_a > i_b:
                    tmp_ans += F[i_b][i_a]
                else:
                    break
            else:
                ans = max(ans, tmp_ans)

    return ans


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


if __name__ == "__main__":
    main()