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)

import Data.Bits

type Mask = Int
type Pair = (Int, Mask)

base :: [Int]
base = [3, 5, 7]

mask :: [Mask]
mask = [1, 2, 4]

seed :: [Pair]
seed = zip base mask

conv :: Pair -> Pair -> Pair
conv (i, s) (j, t) = (i * 10 + j, s .|. t)

gen :: [Pair]
gen = seed ++ [conv pre post | pre <- gen, post <- seed]

ans :: [Int]
ans = [i | (i, s) <- gen, s == 7]

main :: IO ()
main = do
    n <- readLn
    print $ length $ takeWhile (< n) ans