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 <bits/stdc++.h>
using namespace std;
#define rep(i, n) for(int i = 0; i < (int)(n); i++)
typedef long long ll;

int main() {
    // ifstream in("data1.txt");
    // cin.rdbuf(in.rdbuf());
    int N;
    cin >> N;
    int ans = 0;

    for(int i = 356; i < N; i++) {
        string is = to_string(i);
        int digit = is.length();
        int num = 0;
        vector<char> v;
        for(int i = 0; i < digit; i++) {
            if(is[i] == '7' || is[i] == '5' || is[i] == '3') {
                num++;
                v.push_back(is[i]);
            }
        }
        if(num == digit) {
            sort(v.begin(), v.end());
            v.erase(unique(v.begin(), v.end()), v.end());
            if(v.size() == digit) {
                // cout << is << endl;
                ans++;
            }
        }
    }

    cout << ans << endl;
}