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 Ruby (2.3.3) (judge verdict: Accepted)

#方針: 753数を全列挙
n = gets.to_i

list = ["7","5","3"]
ary = []

(3..9).each do |digit|
  (0..3**digit-1).each do |bit|
    tmp = ""
    (0..bit.to_s(3).rjust(digit,"0").length-1).each do |i|
      tmp += list[bit.to_s(3).rjust(digit,"0")[i].to_i]
    end
    ary << tmp
  end
end

ary.each_with_index do |num, i|
  f7=f5=f3 = false
  num.chars do |c|
    case c
    when "7"
      f7=true
    when "5"
      f5=true
    when "3"
      f3 = true
    end
    if f7&&f5&&f3
      ary[i]  = [num,true]
    else
      ary[i] = [num,false]
    end
  end
end

ans = 0
ary.each do |a|
  if a[0].to_i <= n && a[1] == true
    ans+=1
  end
end
p ans