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 Python (3.4.3) (judge verdict: Runtime Error)

def rec(n):
    if n == 0:
        memo[n] = 0
        return memo[n]
    if memo[n] != -1:
        return memo[n]
    res = n
    pow6 = [1]
    pow9 = [1]
    for i in range(1, n):
        if 6 ** i > n:
            break
        pow6.append(6 ** i)
    
    for j in range(1, n):
        if 9 ** j > n:
            break
        pow9.append(9 ** j)
    L = set(pow6 + pow9)
    
    for k in L:
        res = min(res, rec(n - k)+1)
        
    memo[n] = res
    return memo[n]
    

N = int(input())
memo = [-1] * (N+1)
print(rec(N))