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)

#![allow(unused)]

use std::{cell, cmp, collections, convert, fmt, io, iter, ops, str};
use io::{Read, Write};

fn read_line() -> String {
    let mut buf = String::new();
    io::stdin().read_line(&mut buf).unwrap();
    buf.trim().to_owned()
}

fn parse_vec<T: str::FromStr>() -> Result<Vec<T>, T::Err> {
    read_line()
        .split_whitespace()
        .map(|e| e.parse())
        .collect()
}

fn main() {
    let n = {
        let ab = parse_vec::<i32>();
        (ab.unwrap()[0])
    };

    let result = (0..n+1).fold(n, |memo, ind| {
        let cc = calc(n, ind);

        if memo > cc {
            return cc;
        }
        memo
    });

    println!("{}", result);
}

fn calc(n: i32, ind: i32) -> i32 {
    let mut cc = 0;
    let mut tmp = ind;
    while tmp > 0 {
        cc += tmp % 6;
        tmp /= 6;
    }
    let mut tmp = n - ind;
    while tmp > 0 {
        cc += tmp % 9;
        tmp /= 9;
    }
    cc
}