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 i,c;
    int keta;
    int flag=0;
    int count=0;
    int sevencount=0;
    int fivecount=0;
    int threecount=0;
    int N;
    
    scanf("%d",&N);
    
    
    for(i=1;i<=N;i++){
        c = i;
        
        while(c>0){
            keta = c % 10;
            if(keta==3){
                threecount++;
            }
            else if(keta==5){
                fivecount++;
            }
            else if(keta==7){
                sevencount++;
            }else{
                flag ++;
            }
            c /= 10;
        }
        
        
        if(threecount>0 && fivecount>0 && sevencount>0 && flag==0){
            count ++;
            //printf("%d\n",i);
        }
        
        threecount = 0;
        fivecount = 0;
        sevencount = 0;
        flag = 0;
        
    }
    
    printf("%d",count);
    

  
    return 0;
    
}