-- <<reminders
import Control.Concurrent
import Text.Printf
import Control.Monad

main =
  forever $ do
    s <- getLine           -- <1>
    forkIO $ setReminder s -- <2>

setReminder :: String -> IO ()
setReminder s  = do
  let t = read s :: Int
  printf "Ok, I'll remind you in %d seconds\n" t
  threadDelay (10^6 * t)                   -- <3>
  printf "%d seconds is up! BING!\BEL\n" t -- <4>
-- >>