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.*;
public class Main{
	//static HashSet<Long> dic = new HashSet<>();
	public static void main(String[] argv){
		run();
	}

	static void run(){
	
		Scanner scan = new Scanner(System.in);
		long n = scan.nextLong();
		System.out.println(dfs(n, 0));
	}
	static int dfs(long n, long s){
		if(s>n){
			return 0;
		} else {
			int count = 0;
			String ss = String.valueOf(s);
			if(ss.contains("3") && ss.contains("5") &&ss.contains("7"))
				count++;
			count += dfs(n, s*10+3) + dfs(n, s*10+5) + dfs(n, s*10+7); 
			return count;
		}
	}
}