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;
typedef long long ll;
typedef pair<int, int> P;
#define REP(i, n) for (int i = 0; i < (int)(n); i++)
#define sc(x) scanf("%lld",&x);
int main(){
    ll n, u, ans = 0; sc(n)
    bool check;
    vector<int> cnt;
    string s;
    queue<int> que;
    que.push(3), que.push(5), que.push(7);
    while (!que.empty()){
        check = true;
        u = que.front(); que.pop();
        s = to_string(u);
        cnt = {0, 0, 0};
        for (int i = 0; i < s.size(); i++){
            if (s[i] == '3') cnt[0]++;
            else if (s[i] == '5') cnt[1]++;
            else if (s[i] == '7') cnt[2]++;
        }
        for (int i = 0; i < 3; i++) if (cnt[i] == 0) check = false;
        if (u*10+3 <= n) que.push(u*10+3);
        if (u*10+5 <= n) que.push(u*10+5);
        if (u*10+7 <= n) que.push(u*10+7);
        if (check) ans += 1;
    }
    cout << ans << endl;
    return 0;
}