Map counter in Haskell

WordCounter.hs

import Data.Map (Map)
import qualified Data.Map as Map
import Control.Monad

-- | Returns a Map with counts of items in a list
count :: (Ord a, Integral b) => [a] -> Map a b
count =
  foldr updateMap Map.empty
    where updateMap v counts
            | Map.member v counts = Map.adjust succ v counts
            | otherwise           = Map.insert v 1 counts

main = do
  putStrLn "Enter words to be counted, separated by spaces"
  input <- fmap words getLine
  let counted = Map.toList (count input)
  forM_ counted (\(key, value) ->
    putStrLn $ concat [key, ": ", show value])