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 Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.util.*;
import java.util.stream.Collectors;

public class Main {

    public static void main(String args[]) {

        // 入力
        Scanner sc = new Scanner(System.in);
        int n = Integer.parseInt(sc.next());
        sc.close();

        // 主処理
        List<String> list = new ArrayList<>();
        list.add("3");
        list.add("5");
        list.add("7");
        for (int i = 0; i < 8; i++) {
            int size = list.size();
            for (int j = 0; j < size; j++) {
                String base = list.get(j);
                list.add(base + 3);
                list.add(base + 5);
                list.add(base + 7);
            }
        }

        List<Long> longList = list.stream().filter(i -> i.contains("3") && i.contains("5") && i.contains("7"))
                .map(i -> Long.parseLong(i)).collect(Collectors.toList());
        longList = new ArrayList<>(new HashSet<>(longList));
        Collections.sort(longList);

        int result = 0;
        for (int i = 0; i < longList.size(); i++) {
            if (longList.get(i) <= (long) n) {
                result++;
            }
        }

        // 出力
        System.out.println(result);
    }
}