output_description: If at least x operations are required to withdraw exactly N yen in total,
  print x.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      N
attempt: n = int(input())
  ans, index6, index9, num6, num9 = 0, 0, 0, 0, 0
  INF = float("inf")
  
  
  def a10_to_n(x, n):
      if x // n:
          return a10_to_n(x // n, n) + str(x % n)
      else:
          return str(x)
  
  
  def index(n, num6, index6, num9, index9):
      val = str(a10_to_n(n, 6))
      for i, j in enumerate(val):
          if int(j) != 0:
              num6 = int(j)
              index6 = len(val) - i - 1
              break
      val = str(a10_to_n(n, 9))
      for i, j in enumerate(val):
          if int(j) != 0:
              num9 = int(j)
              index9 = len(val) - i - 1
              break
      return num6, index6, num9, index9
  
  
  num6, index6, num9, index9 = index(n, num6, index6, num9, index9)
  while index6 > 1 or index9 > 1:
      if 6**index6 <= 9**index9:
          n -= num9 * 9**index9
          ans += num9
      else:
          n -= num6 * 6**index6
          ans += num6
      num6, index6, num9, index9 = index(n, num6, index6, num9, index9)
  
  a = [INF for _ in range(n + 1)]
  a[n] = 0
  for i in range(n, -1, -1):
      if i - 9 >= 0:
          a[i - 9] = min(a[i] + 1, a[i - 9])
      if i - 6 >= 0:
          a[i - 6] = min(a[i] + 1, a[i - 6])
      if i - 1 >= 0:
          a[i - 1] = min(a[i] + 1, a[i - 1])
  print(ans + a[0])
  
problem_description: 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.
samples: [{"input": "127", "output": "4\n    \n\nBy withdrawing 1 yen, 9 yen, 36(=6^2) yen and 81(=9^2) yen, we can withdraw\n127 yen in four operations.\n\n* * *"}, {"input": "3", "output": "3\n    \n\nBy withdrawing 1 yen three times, we can withdraw 3 yen in three operations.\n\n* * *"}, {"input": "44852", "output": "16"}]