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 Rust (1.15.1) (judge verdict: Accepted)

use std::io;
use std::str::FromStr;
use std::cmp::min;

fn input<T:FromStr>() -> T {
    let mut line: String = String::new();
    io::stdin().read_line(&mut line);
    line.trim().parse().ok().unwrap()
}

fn main() {
    let n: usize = input();
    let mut dp: Vec<u64> = vec![0; n+1];
    for i in 1..(n+1) {
        let mut min_val = dp[i-1] + 1;        
        let mut six_candidate = 6;
        while six_candidate <= i {
            min_val = min(min_val, dp[i - six_candidate as usize] + 1);
            six_candidate *= 6;
        }
        let mut nine_candidate = 9;
        while nine_candidate <= i {
            min_val = min(min_val, dp[i - nine_candidate as usize] + 1);
            nine_candidate *= 9;
        }
        dp[i] = min_val;
    }
    println!("{}", dp[n]);
}