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 <bits/stdc++.h>
using namespace std;

int main(){
    int n;
    cin >> n;
    queue<int> q;
    int ans=0;
    q.push(3);
    q.push(5);
    q.push(7);
    int tmp;
    int i,j,k;
    while(q.front()<=n){
            tmp=q.front();
            q.push(tmp*10+3);
            q.push(tmp*10+5);
            q.push(tmp*10+7);
            q.pop();
            i=0; j=0; k=0;
            while(tmp>0){
                if(tmp%10==3)i++;
                else if(tmp%10==5)j++;
                else if(tmp%10==7)k++;
                tmp/=10;
            }
            if(i>0&&j>0&&k>0)ans++;
    }
    cout << ans << endl;
}