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 {
	public static void main (String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		if (n < 357) {
		    System.out.println(0);
		    return;
		}
		int now = 1000;
		ArrayDeque<Integer> deq = new ArrayDeque<>();
        ArrayDeque<Integer> next = new ArrayDeque<>();
        deq.add(0);
        int size = 0;
		while (deq.size() > 0) {
		    int x = deq.poll();
		    if (x > n) {
		        continue;
		    }

		    next.add(x * 10 + 3);
		    next.add(x * 10 + 5);
		    next.add(x * 10 + 7);
		    if (x > Integer.MAX_VALUE / 10 - 10) {
		        break;
		    }
		    deq.add(x * 10 + 3);
		    deq.add(x * 10 + 5);
		    deq.add(x * 10 + 7);
		}
		int count = 0;
		while (next.size() > 0) {
		    int x = next.poll();
		    if (x <= n && is753(x)) {
		        count++;
		    }
		}
		System.out.println(count);
	}
	
	static boolean is753(int x) {
	    int[] mod = new int[10];
	    while(x > 0) {
	        mod[x % 10]++;
	        x /= 10;
	    }
	    return mod[3] > 0 && mod[7] > 0 && mod[5] > 0;
	}
}