data Command = Forward Int | Down Int | Up Int
type Position = (Int,Int)
type AimPosition = (Int,Int,Int)

readCmd :: String -> Command
readCmd s = case cmd of
    "forward" -> Forward $ read num
    "down" -> Down $ read num
    "up" -> Up $ read num
    _ -> error $ "unknown command" ++ cmd
    where (cmd:num:xs) = words s

moveSub :: Position -> Command -> Position
moveSub (h,d) (Forward f) = (h+f,d)
moveSub (h,d) (Down f) = (h,d+f)
moveSub (h,d) (Up f) = (h,d-f)

applyCommands :: [Command] -> Position
applyCommands = foldl moveSub (0,0)

moveSubAim :: AimPosition -> Command -> AimPosition
moveSubAim (h,d,a) (Forward f) = (h+f,d+a*f,a)
moveSubAim (h,d,a) (Down f) = (h,d,a+f)
moveSubAim (h,d,a) (Up f) = (h,d,a-f)

applyCommandsAim :: [Command] -> AimPosition
applyCommandsAim = foldl moveSubAim (0,0,0)

main :: IO ()
main = do
    input <- getContents
    let commands = map readCmd $ lines input
    putStr "part 1: "
    print $ uncurry (*) $ applyCommands commands
    putStr "part 2: "
    print $ (\(x,y,_) -> x*y) $ applyCommandsAim commands
    return ()