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::vec::Vec;
use std::cmp::*;

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

fn read_vec<T: std::str::FromStr>() -> Vec<T> {
    read::<String>().split_whitespace().map(|e| e.parse().ok().unwrap()).collect()
}
// [9, 81, 729, 6561, 59049, 531441]
// [6, 36, 216, 1296, 7776, 46656, 279936]
fn main() {
  solve2();
}

fn solve2() {
  let n: usize = read();

  let mut dp: Vec<u64> = vec![std::u64::MAX; n+1];
  dp[0] = 0;

  for i in 1..n+1 {
    let mut power = 1;
    while power <= i {
      dp[i] = min(dp[i], dp[i - power] + 1);
      power *= 6;
    }

    power = 1;
    while power <= i {
      dp[i] = min(dp[i], dp[i - power] + 1);
      power *= 9;
    }
  }
  println!("{}", dp[n]);
}