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++14 (GCC 5.4.1) (judge verdict: Wrong Answer)

#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define MOD 1000000007
bool ass[MOD];
int N;
long long ask(long long a){
  int b=0,c=0,d=0;
  while(a>0){
    if(a%10==3) b=1;
    if(a%10==5) c=1;
    if(a%10==7) d=1;
    a=a/10;
  }
  if(b==1){
    if(c==1){
    if(d==1){
    return 1;
    }
    }
  }
  else 
    return 0;
}
void aii(long long a){
  if(ask(a)==1){
    ass[a]=true;
  }
  if(a<N/10){
  aii(a*10+3);
  aii(a*10+5);
  aii(a*10+7);
  }
}
int main (){
  int aaa=0;
  cin>>N;
  aii(3);
  aii(5);
  aii(7);
  rep(i,N){
    if(ass[i+1]) aaa++;
  }
  cout<<aaa;
}