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: Time Limit Exceeded)

using System;
using System.Text;
using static System.Console;
namespace a755
{
    class a755
    {
        static void Main(string[] args)
        {
            long x = long.Parse(ReadLine());
            long op = 0;
            for (long i = 357; i <= x; i++)
            {
                string t = i.ToString();
                if (t.Contains("0") || t.Contains("1") || t.Contains("2") || t.Contains("4") || t.Contains("6") || t.Contains("8") || t.Contains("9"))
                {

                }
                else if (t.Contains("7") && t.Contains("5") && t.Contains("3"))
                {
                    op = ++op;
                }
            }
            WriteLine(op);
        }
    }
}