Problem:
Score: 200 points

Problem Statement

The number 105 is quite special - it is odd but still it has eight divisors.
Now, your task is this: how many odd numbers with exactly eight positive divisors are there between 1 and N (inclusive)?

Constraints

N is an integer between 1 and 200 (inclusive).

Input

Input is given from Standard Input in the following format:

N

Output

Print the count.

Sample Input 1

105

Sample Output 1

1

Among the numbers between 1 and 105, the only number that is odd and has exactly eight divisors is 105.

Sample Input 2

7

Sample Output 2

0

1 has one divisor. 3, 5 and 7 are all prime and have two divisors. Thus, there is no number that satisfies the condition.

Solution in Haskell (GHC 7.10.3) (judge verdict: Accepted)

import Data.List

main :: IO ()
main = do
  n <- getInt
  print $ countIf ((== 8) . length . divisors) [1,3..n]

divisors :: Int -> [Int]
divisors n = concat [nub [x, n `div` x] | x <- takeWhile (\x -> x * x <= n) [1..], n `mod` x == 0]

getInt :: IO Int
getInt = read <$> getLine

countIf :: (a -> Bool) -> [a] -> Int
countIf f = length . filter f