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, m = gets.chomp.split.map(&:to_i)
#ary = []; n.times { cakes << gets.chomp.split.map(&:to_i).to_a } 
#def cb(i);	i==1 ? 1 : -1;end
n = gets.chomp.to_i.to_s
ans = 0
ary = ['3','5','7']
for i1 in 0..2
	for i2 in 0..2
		for i3 in 0..2
			for i4 in 0..2
				for i5 in 0..2
					for i6 in 0..2
						for i7 in 0..2
							for i8 in 0..2
								for i9 in 0..2
									ans +=1 if "#{ary[i1]}#{ary[i2]}#{ary[i3]}#{ary[i4]}#{ary[i5]}#{ary[i6]}#{ary[i7]}#{ary[i8]}#{ary[i9]}".to_i < n
								end
							end
						end
					end
				end
			end
		end
	end
end
p ans