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: Accepted)

#include <iostream>
#include <iomanip>
#include <vector>
#include <string>
#include <algorithm>
#include <math.h>
#include <map>
#include <string.h>
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<ll, ll> P;
int ans=0;

void check(int n,int num){
    
    
        //357がひとつ以上あればカウント
        bool san=0;
        bool go=0;
        bool nana=0;
        string str = to_string(num);
        for(int i = 0; i < (int)str.size(); ++i){
            if(str[i]=='3'){san =true;}
            if(str[i]=='5'){go  =true;}
            if(str[i]=='7'){nana=true;}
        }
        if(san&&go&&nana){ans++;}

        if(10*(double)num+3<=n){check(n,10*num+3);}
        if(10*(double)num+5<=n){check(n,10*num+5);}
        if(10*(double)num+7<=n){check(n,10*num+7);}

    

}

int main()
{

//整数値の入力
int n;
cin >> n;
int i;


check(n,3);
check(n,5);
check(n,7);



//回答
cout <<ans<< endl;
return 0;
}