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 exist(long y, long tag){
  while(y != 0){
    if(tag == y % 10)
      return 1;
    else y=y/10;
  }
  return 0;
}

long count753(long x, long y){
  if (x < y)
    return 0;
  else{
    long yes = exist(y,3)&&exist(y,5)&&exist(y,7);
    long ret = yes + count753(x,y*10+3) + count753(x,y*10+5) + count753(x,y*10+7);
    return ret;
  }
}

int main(){
  long x;
  scanf("%ld",&x);
  printf("%ld\n",count753(x,0));

  return 0;
}