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: Runtime Error)

n = gets.chomp.to_i

num_len = 0
num = 1
while true
	num_s = num.to_s(4)
	ok_7 = false
	ok_5 = false
	ok_3 = false
	ok = true
	for i in 0..num_s.length-1
		if num_s[i] == '3'
			ok_7 = true
			num_s[i] = '7'
		elsif num_s[i] == '2'
			ok_5 = true
			num_s[i] = '5'
		elsif num_s[i] == '1'
			ok_3 = true
			num_s[i] = '3'
		else
			ok = false
			break
		end
	end
	if ok && ok_7 && ok_5 && ok_3
		num_len += 1
	end
	num += 1
	if num_s.to_i > n
		break
	end
end

puts num_len.to_s
	end
	num += 1
	if num_s.to_i > n
		break
	end
end

puts numbers_753.length.to_s