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 Scala (2.11.7) (judge verdict: Accepted)

import java.io.{BufferedReader, InputStream, InputStreamReader}
import java.util.StringTokenizer

import scala.collection.mutable
import scala.util.Sorting
import math.{abs, max, min}

object Main {
  val MOD = 1000000007
  def solve(): Unit = {
    val sc = new InputReader(System.in)
    val N = sc.nextInt()

    val INF =100001
    val dp = Array.fill[Int](N + 1)(INF)
    dp(0) = 0
    var d = 6
    for {
      _ <- 1 to 6
    } {
      (1 to N) foreach { i =>
        if (i - d >= 0) dp(i) = min(dp(i), dp(i - d) + 1)
      }
      d *= 6
    }
    d = 9
    for {
      _ <- 1 to 5
    } {
      (1 to N) foreach { i =>
        if (i - d >= 0) dp(i) = min(dp(i), dp(i - d) + 1)
      }
      d *= 9
    }

    val ix = dp.lastIndexWhere(_ != INF)
    val ans = if (ix !=  -1) {
      dp(ix) + (N - ix)
    } else {
      N
    }

    println(ans)
  }


  def main(args: Array[String]): Unit = {
    solve()
  }


  class InputReader(val stream: InputStream) {
    private val reader = new BufferedReader(new InputStreamReader(stream), 32768)
    private var tokenizer: StringTokenizer = null

    def next: String = {
      while (tokenizer == null || !tokenizer.hasMoreTokens)
        tokenizer = new StringTokenizer(reader.readLine)
      tokenizer.nextToken
    }

    def nextInt(): Int = next.toInt
    def nextLong(): Long = next.toLong
    def nextChar(): Char = next.charAt(0)
  }


}