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)

s = gets.chomp

def get_count keta, max
  ret = 0
  flg = max.to_s.length > keta ? false : true
  (3 ** keta).times do |i|
    tmp = i.to_s(3).rjust(keta, '0')
    if tmp.include?('0') && tmp.include?('1') && tmp.include?('2')
      if flg
        ret += 1 if tmp.gsub('0', '3').gsub('1', '5').gsub('2', '7').to_i <= max
      else
        ret += 1
      end
    end
  end
  ret
end

ret = 0
s.length.times do |i|
  ret += (get_count (i+1), s.to_i)
end
puts ret