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::cmp;

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

fn main() {
    let n = read::<usize>();
    let max = usize::max_value();
    let mut v: Vec<usize> = vec![max;n+1];
    v[0] = 0;
    for i in 0..n {
        if v[i] + 1 < v[i+1] {
            v[i+1] = v[i] + 1;
        }
        let mut j = 6;
        while i + j <= n {
            v[i+j] = cmp::min(v[i+j],v[i]+1);
            j *= 6;
        }
        j = 9;
        while i + j <= n {
            v[i+j] = cmp::min(v[i+j],v[i]+1);
            j *= 9;
        }
    }
    println!("{}",v[n]);
}