Problem:
Score : 300 points

Problem Statement

To make it difficult to withdraw money, a certain bank allows its customers to withdraw only one of the following amounts in one operation:

1 yen (the currency of Japan)

6 yen, 6^2(=36) yen, 6^3(=216) yen, ...

9 yen, 9^2(=81) yen, 9^3(=729) yen, ...

At least how many operations are required to withdraw exactly N yen in total?

It is not allowed to re-deposit the money you withdrew.

Constraints

1 \leq N \leq 100000

N is an integer.

Input

Input is given from Standard Input in the following format:

N

Output

If at least x operations are required to withdraw exactly N yen in total, print x.

Sample Input 1

127

Sample Output 1

4

By withdrawing 1 yen, 9 yen, 36(=6^2) yen and 81(=9^2) yen, we can withdraw 127 yen in four operations.

Sample Input 2

3

Sample Output 2

3

By withdrawing 1 yen three times, we can withdraw 3 yen in three operations.

Sample Input 3

44852

Sample Output 3

16

Solution in C# (Mono 4.6.2.0) (judge verdict: Wrong Answer)

using System;
using System.Collections.Generic;
using System.Linq;
using static System.Console;

public class Program
{
    static int result = new int();
    static List<int> resultList = new List<int>();
    public static void Main()
    {
        int N = int.Parse(ReadLine());

        List<int> divisorList = new List<int>();
        divisorList.Add(1);

        int sixPow = 6;
        while (sixPow < N)
        {
            divisorList.Add(sixPow);
            sixPow = sixPow * 6;
        }
        int ninePow = 9;
        while (ninePow < N)
        {
            divisorList.Add(ninePow);
            ninePow = ninePow * 9;
        }
        divisorList.Sort();
        divisorList.Reverse();

        getResult(divisorList, N, 0, ref result);
        //for (int i = 0; i < divisorList.Count; i++)
        //{
        //    if (N % divisorList[i] == 0)
        //    {
        //        resultList.Add(N / divisorList[i]);
        //    }
        //    else
        //    {
        //        for (int j = 0; j < divisorList.Count - 1; j++)
        //        {
        //            if (N % divisorList[i] % divisorList[j] == 0)
        //            {
        //                resultList.Add(N / divisorList[i] + N % divisorList[i] / divisorList[j]);
        //            }
        //        }
        //    }
        //}
        if (resultList.Count == 0)
        {
            WriteLine(N);
            ReadLine();
            return;
        }
        WriteLine(resultList.Min());
    }

    public static void getResult(List<int> divisorList, int N, int count, ref int res)
    {
        for (int i = count; i < divisorList.Count; i++)
        {
            if (divisorList[i] != 1 && N % divisorList[i] == 0)
            {
                resultList.Add(res + N / divisorList[i]);
                return;
            }
            else
            {
                if (divisorList[i] == 1)
                {
                    resultList.Add(res + N / divisorList[i]);
                    return;
                }
                else
                {
                    res += N / divisorList[i];
                    getResult(divisorList, N % divisorList[i], i + 1, ref res);
                    res -= N / divisorList[i];
                }
            }
        }
    }
}