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: Wrong Answer)

N = STDIN.gets.chomp.to_i


$arr = ['7', '5', '3']

def increment(i)
  if $arr.length == i
    $arr.push('3')
    return
  end

  case $arr[i]
  when '3'
    $arr[i] = '5'
  when '5'
    $arr[i] = '7'
  when '7'
    $arr[i] = '3'
    increment(i+1)
  end
end

cnt = 0
while true do
  cnt += 1 if $arr.include?('7') && $arr.include?('5') && $arr.include?('3')
  increment(0)
  # puts $arr.join(',')
  i = $arr.reverse.join('').to_i
  # puts i
  break if i > N
end
puts cnt