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: Accepted)

using System;
using static System.Console;

class Program
{
    public static void Main()
    {
	int n = int.Parse(ReadLine());

	// 1, (1)
	// 6, 6^2, ..., 6^6 (6)
	// 9, 9^2, ..., 9^5 (5)

	int ans = n + 1;

	for (int N = 1; N <= n; N++)
	{
	    int res = 0;
	    int n9 = n;
	    
	    int n6 = N;
	    int k = 6;
	    while (k > 0 && n6 > 0)
	    {
		int amount = (int) Math.Pow(6, k);
		int c = n6 / amount;
		res += c;
		n6 -= c * amount;
		n9 -= c * amount;
		k--;
	    }

	    k = 5;
	    while (k > 0 && n9 > 0)
	    {
		int amount = (int) Math.Pow(9, k);
		int c = n9 / amount;
		res += c;
		n9 -= c * amount;
		k--;
	    }

	    res += n9;
	    ans = Math.Min(ans, res);
	}

	WriteLine(ans);
    }
}