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>
#include<string.h>
int main(void){
  int a;
  scanf("%d",&a);
  int count=0;
char c[20];
for(int i=357;i<a+1;i++){
    
snprintf(c, 20, "%d",i);
 int it;
 it = strlen(c);
 for(int j=0;j<it;j++){
   if(c[j] !='7' && c[j] != '5' && c[j] != '3'){
     break;
   } 
   int flaga=1;
   int flagb=1; 
   int flagc=1;
   for(int j=0;j<it;j++){
     if(c[j]=='7'){
       flaga = 0;}
     if(c[j]=='5'){
       flagb = 0;
     }
     if(c[j]=='3'){
       flagc =0;
     }
   }
     if(j==it-1&&flaga==0&&flagb==0&&flagc==0)
{
     count++;
   }
 }
 }
  printf("%d",count);
  return 0;
  }