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: Accepted)

#include<stdio.h>

long int kotae=0;

int check(long int);
int saiki(long int,long int);

int main(void){
  long int i,n;
  scanf("%ld",&n);
  saiki(0,n);
  printf("%ld",kotae);
  return 0;
}

int check(long int n){
  int a=0,b=0,c=0;
  for(;n>0;n=n/10){
    switch(n%10){
      case 3:
        a++;
        break;
      case 5:
        b++;
        break;
      case 7:
        c++;
        break;
    }
  }
  if(a*b*c==0){
    return 0;
  }else{
    return 1;
  }
}

int saiki(long int n,long int max){
  if(n<=max){
    kotae+=check(n);
    saiki(10*n+3,max);
    saiki(10*n+5,max);
    saiki(10*n+7,max);
  }
}