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)

#! /usr/bin/env ruby

N = STDIN.read.to_i
SU = [357, 375, 537, 573, 735, 753]
NS = [3, 5, 7]


def sgs_fac(i, m)
  cnt = 0
  NS.repeated_permutation(i) {|arr| 
    j = arr.join('').to_i
    if j <= m && arr.uniq.length == 3
      cnt = cnt + 1
    end
  }
  return cnt
end

def sgs()
  if N < 1000
    return SU.select{|i| i < N}.length
  end
  l = N.to_s.length
  cnt = 0
  i = l
  while i > 0
    cnt = cnt + sgs_fac(i, N)
    i = i - 1
  end

  return cnt
end

puts sgs()