using System;
using System.Collections.Generic;
using System.Linq;
using System.Collections;
using System.Linq.Expressions;

static class Program
{
    static void Main()
    {
        new Magatro().Solve();
    }
}

struct P
{
    public string Name;
    public int Time;
    public P(string s, int time)
    {
        Name = s;
        Time = time;
    }
}

class Magatro
{
    private int N;
    private int[][] F;
    private bool[] Use;
    private void Scan()
    {
        N = int.Parse(Console.ReadLine());
        F = new int[N][];
        for (int i = 0; i < N; i++)
        {
            F[i] = Console.ReadLine().Split(' ').Select(int.Parse).ToArray();
        }
    }

    public int Sol()
    {
        int first = -1;
        for (int i = 0; i < N; i++)
        {
            if (!Use[i])
            {
                first = i;
                break;
            }
        }
        if (first == -1)
        {
            return 0;
        }
        Use[first] = true;
        int max = -1;
        for (int second = first + 1; second < N; second++)
        {
            if (Use[second]) continue;

            Use[second] = true;
            var i = Sol() + F[first][second];
            if (max < i)
            {
                max = i;
            }
            Use[second] = false;
        }
        Use[first] = false;
        return max;
    }

    public void Solve()
    {
        Scan();
        Use = new bool[N];
        Console.WriteLine(Sol());
    }

}