Solution to facebook puzzle 'Hoppity', in Haskell

Hoppity.hs

-- Facebook puzzle #1 - Hors d'oeuvres
-- http://www.facebook.com/careers/puzzles.php?puzzle_id=7

output 0 = return ()
output x = 
	putStrLn (gethop x)
	output (x - 1)

gethop x
	| div3 x && div5 x = "Hop\n"
	| div3 x = "Hoppity\n"
	| div5 x = "Hophop\n"
	| otherwise = ""
	
divides y x = x `mod` y == 0 
div3 = divides 3
div5 = divides 5
		
main = do
	instr <- getLine
	output (read instr::Int)