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 Ruby (2.3.3) (judge verdict: Accepted)

N = gets.to_i
r = N

def calc(r, i)
  if r < 6
    return [r, i]
  end

  j = 0
  v = 1
  while r >= v
    j += 1
    v = 6 ** j
  end

  result = []
  result << calc(r - 6 ** (j - 1), i + 1)

  if r >= 9
    j = 0
    v = 1
    while r >= v
      j += 1
      v = 9 ** j
    end

    result << calc(r - 9 ** (j - 1), i + 1)
  end

  result
end

d = calc(r, 0).flatten
result = []
0.step(d.size - 1, 2) do |i|
  result << d[i + 1] + d[i]
end
p result.min