gistfile1.hs

import Control.Monad
import Data.Map
import Data.Maybe

newtype Triplet = Triplet (Integer, Integer, Integer)

applyMany :: Integer -> (a -> a) -> a -> a
applyMany 0 f a = a
applyMany n f a = applyMany (n - 1) f $! (f a)

f :: Triplet -> Triplet
f (Triplet (a, b, c)) = Triplet ((a + b + c) `mod` 10007, a, b)

h :: Integer -> Integer
h 1 = 0
h 2 = 0
h 3 = 1
h n = let Triplet (a, b, c) = applyMany (n - 3) f $ Triplet (1, 0, 0)
      in a

main = do
  n <- liftM (read :: String -> Integer) getLine
  putStrLn $ show $ h n