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::str::FromStr;
use std::io::stdin;

fn main() {
    let n = read::<usize>();
    let mut dp: Vec<usize> = vec![123456; 1000000];
    dp[0] = 0;
    for i in 0..n+1 {
        let mut nine: usize = 9;
        let mut six: usize  = 6;
        while nine <= n+1 {
            dp[i+nine] = std::cmp::min(dp[i]+1, dp[i+nine]);
            nine *= 9;
        }
        while six <= n+1 {
            dp[i+six] = std::cmp::min(dp[i]+1, dp[i+six]);
            six *= 6;
        }
        dp[i+1] = std::cmp::min(dp[i]+1,dp[i+1]);
    }

    println!("{}", dp[n]);
}

fn read<T: FromStr>() -> T {
    let mut line = String::new();
    stdin().read_line(&mut line).ok();
    line.trim().parse().ok().unwrap()
}
/*
fn read_vec<T: FromStr>() -> Vec<T> {
    let mut line: String = String::new();
    stdin().read_line(&mut line).ok();
    line.trim().split_whitespace()
        .map(|i| i.parse().ok().unwrap()).collect()
}
*/