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,count=0,kisyutu[3];char CN[8];
  scanf("%d",&N);
  for(int i=1;i<N+1;i++){
      for(int k=0;k<3;k++) kisyutu[k]=0;
      snprintf(CN,8,"%d",i);
      for(int j=0;j<8;j++){
        if(CN[j]=='\0'){
          if((kisyutu[0]+kisyutu[1]+kisyutu[2]) == 3){
             count++;
          }
          break;
        }
        if(CN[j]-'0'==3) kisyutu[0]=1;
        else if(CN[j]-'0'==5) kisyutu[1]=1;
        else if(CN[j]-'0'==7) kisyutu[2]=1;
        else break;
      }
  }
  printf("%d",count);
  return 0;
}