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 Haskell (GHC 7.10.3) (judge verdict: Wrong Answer)

main = do
    n <- read <$> getLine :: IO Int
    print $ length (filter ((<n) . read) (num753Numbers 10 ""))

num753Numbers :: Int -> String -> [String]
num753Numbers maxDigit xs
    | length xs > maxDigit = []
    | otherwise = let list7 = num753Numbers maxDigit ('7':xs)
                      list5 = num753Numbers maxDigit ('5':xs)
                      list3 = num753Numbers maxDigit ('3':xs)
                      includes753 = '7' `elem` xs && '5' `elem` xs && '3' `elem` xs
                      includesOnly753 = and (map (`elem` "753") xs)
                      list = if includes753 && includesOnly753 then [xs] else []
                  in concat [list7, list5, list3, list]