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(void){
    int n, cnt=0;
    cin >> n;
    if(n < 357){
        cout << "0\n";
        return 0;
    }
    int start = 357;
    if(n>500000000){
        start = 499999999;
        cnt += 14384;
    }
    for(int i=start;i<=n;i=i+2){
        int j=i, flg=1, c3=0, c5=0, c7=0;
        while(j>0){
            int k = j%10;
            if(k!=3 && k!=5 && k!=7){
                flg = 0;
                break;
            }
            if(k==3) ++c3;
            if(k==5) ++c5;
            if(k==7) ++c7;
            j /= 10;
            if(j > 0 && j%2==0){
                flg = 0;
                break;
            }
        }
        if(flg){
            if(c3>0 && c5>0 && c7>0) ++cnt;
        }
    }
    cout << cnt << endl;
}