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# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
using System.Collections.Generic;
using System.Linq;
using System.IO;
using System.Text;
using static System.Console;
using static System.Math;

namespace AtCodeeeer
{
    class AtCOOOOOOOOOOOder
    {
        static void Main(string[] args)
        {
            int n = int.Parse(ReadLine());

            Queue<string> num = new Queue<string>();
            List<long> List = new List<long>();

            num.Enqueue("3");
            num.Enqueue("5");
            num.Enqueue("7");
            while (num.Count > 0)
            {
                string tmp = num.Dequeue();
                if (tmp.Contains("3"))
                    if (tmp.Contains("5"))
                        if (tmp.Contains("7"))
                            List.Add(long.Parse(tmp));
                if (tmp.Length < 11)
                {
                    num.Enqueue(tmp + "3");
                    num.Enqueue(tmp + "5");
                    num.Enqueue(tmp + "7");
                }
            }

            WriteLine(List.Count(x => x <= n && x >= 357));
        }
    }
}