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 C (GCC 5.4.1) (judge verdict: Time Limit Exceeded)

#include<stdio.h>

int main(){
	int N;
	int cnt = 0;
	int three = 0;
	int five = 0;
	int seven = 0;
	int dig;
	int other=1;
	scanf("%d",&N);
	while(N>356){
		int M = N;
		while(M!=0){
			dig = M%10;
			if(dig==3)three = 1;
			else if(dig==5)five = 1;
			else if(dig==7) seven = 1;
			else{
				other = 0;
				break;
			}
			M = M/10;
		}
		if(three&&five&&seven&&other) cnt++;
		N--;
		three = 0;
		five = 0;
		seven = 0;
		other = 1;
	}
	printf("%d\n",cnt);
	return 0;
}