using System;
using System.Collections.Generic;
using System.Text;
using System.Linq;

class Program
{
    public void Proc()
    {
        int IdolCount = int.Parse(Reader.ReadLine());

        this.Aisho = new int[IdolCount, IdolCount];
        for (int i = 0; i < IdolCount; i++)
        {
            int[] inpt = Reader.ReadLine().Split(' ').Select(a => int.Parse(a)).ToArray();
            for (int j = 0; j < inpt.Length; j++)
            {
                this.Aisho[i, j] = inpt[j];
            }
        }
        int ans = this.GetAns(0, 0);
        Console.WriteLine(ans);
    }


    private int GetAns(int idx, long flags)
    {
        long key = (long)1 << idx;
        if ((key & flags) > 0)
        {
            return GetAns(idx + 1, flags);
        }

        if (dic.ContainsKey(flags))
        {
            return dic[flags];
        }

        int ans = 0;

        for (int i = idx + 1; i < Aisho.GetLength(0); i++)
        {
            long pairKey = (long)1 << i;
            if ((flags & pairKey) > 0)
            {
                continue;
            }
            int ret = GetAns(idx + 1, flags + key + pairKey) + Aisho[idx, i];
            ans = Math.Max(ret, ans);
        }
        dic[flags] = ans;
        return ans;
    }

    private Dictionary<long, int> dic = new Dictionary<long, int>();

    private int[,] Aisho;

    


    public class Reader
    {
        public static bool IsDebug = false;
        private static String PlainInput = @"





6
-1 14 29 35 39 8
14 -1 35 41 34 3
29 35 -1 14 21 21
35 41 14 -1 12 42
39 34 21 12 -1 28
8 3 21 42 28 -1





";
        private static System.IO.StringReader Sr = null;
        public static string ReadLine()
        {
            if (IsDebug)
            {
                if (Sr == null)
                {
                    Sr = new System.IO.StringReader(PlainInput.Trim());
                }
                return Sr.ReadLine();
            }
            else
            {
                return Console.ReadLine();
            }
        }
    }
    static void Main()
    {
#if DEBUG
        Reader.IsDebug = true;
#endif
        Program prg = new Program();
        prg.Proc();
    }
}