Problem:
Score : 300 points

Problem Statement

You are given an integer N. Among the integers between 1 and N (inclusive), how many Shichi-Go-San numbers (literally "Seven-Five-Three numbers") are there?

Here, a Shichi-Go-San number is a positive integer that satisfies the following condition:

When the number is written in base ten, each of the digits 7, 5 and 3 appears at least once, and the other digits never appear.

Constraints

1 \leq N < 10^9

N is an integer.

Input

Input is given from Standard Input in the following format:

N

Output

Print the number of the Shichi-Go-San numbers between 1 and N (inclusive).

Sample Input 1

575

Sample Output 1

4

There are four Shichi-Go-San numbers not greater than 575: 357, 375, 537 and 573.

Sample Input 2

3600

Sample Output 2

13

There are 13 Shichi-Go-San numbers not greater than 3600: the above four numbers, 735, 753, 3357, 3375, 3537, 3557, 3573, 3575 and 3577.

Sample Input 3

999999999

Sample Output 3

26484

Solution in Rust (1.15.1) (judge verdict: Accepted)

use std::io::Read;
use std::collections::VecDeque;
fn main() {
    let mut buf = String::new();

    std::io::stdin().read_to_string(&mut buf).unwrap();

    let mut iter = buf.split_whitespace();
    let n = iter.next().unwrap().parse::<i64>().unwrap();
    let mut queue = VecDeque::<i64>::new();
    queue.push_back(3);
    queue.push_back(5);
    queue.push_back(7);
    let mut ans = 0;    
    //while queue.
    while !queue.is_empty() {
        let current = queue.pop_front().unwrap();
        if current > n { continue; }
        if ['3','5','7'].into_iter().all(|x| current.to_string().contains(*x)) { ans += 1; }
        queue.push_back(10 * current + 3);
        queue.push_back(10 * current + 5);
        queue.push_back(10 * current + 7);
    }

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