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 <cstdlib>
using namespace std;


int main()
{

	int N;
	cin >> N;

	string S;
	int val[3] = { 3,5,7 };
	int digit_count = 0;
	int ans_count = 0;
	int frag3=0, frag5=0, frag7=0;

	for (int i = 1; i < N; i++) {
		S = to_string(i);
		digit_count = 0;
		frag3 = 0, frag5 = 0, frag7 = 0;
		for (int j_digit = 0; j_digit < (int)S.length(); j_digit++) {
			if (stoi(S.substr(j_digit, 1))==3) {
				frag3++;
				digit_count++;
			}
			else if (stoi(S.substr(j_digit, 1)) == 5) {
				frag5++;
				digit_count++;
			}
			else if (stoi(S.substr(j_digit, 1)) == 7) {
				frag7++;
				digit_count++;
			}
		}
		if (digit_count == (int)S.length() && frag3*frag5*frag7 > 0) {
			cout << i << endl;
			ans_count++;
		}
	}


	std::cout << ans_count << endl;
}