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 <iostream>
#include <string>
#include <vector>
#include <cmath>
#include <queue>
#include <map>
#include<algorithm>

using namespace std;

bool is753(int n) {
	vector<int> cnt(3);
	while (n) {
		cnt[((n % 10) - 3) / 2]++;
		n /= 10;
	}
	for (int i = 0; i < 3; i++) {
		if (!cnt[i]) {
			return false;
		}
	}
	return true;
}

int main() {
	int n;
	cin >> n;
	int dig = 0;
	{int tmp = n;
	while (tmp) {
		dig++;
		tmp /= 10;
	}
	}
	
	int ans = 0;
	if (dig >= 3) {

		vector<int> cnt(dig+1);
		cnt[3] = 3 * 2 * 1;
		for (int i = 4; i < dig +1;i++) {
			cnt[i] = cnt[i - 1] * 3;
			
		}


		
		for (int d = 3; d < dig;d++) {
			ans += cnt[d];
			
		}
		
		for (int i = 0; i < (1 << (2 * dig)); i++) {
			int num = 0;
			bool isP753 = true;
			for (int d = 0; d < dig; d++) {
				int tmp = (i >> (2 * d)&3);
				//cout << tmp << " "<< i<< endl;
				if (tmp == 3) {
					isP753 = false;
				}
				else {
					num = num * 10 + 2 * (tmp)+3;
				}
			}

			

			if (isP753 &&num < n) {
				//cout << num << endl;
				if (is753(num)) {
					ans++;
				}
			}
		}
		
		

	}
	cout << ans << endl;
}