{-# LANGUAGE ExistentialQuantification, RankNTypes #-}

data Yoba = Yoba { imya :: String }
data Chislo = Chislo { vladelec :: Yoba, znachenie :: forall a. (a -> a) -> (a -> a) }


bratecYoba = Yoba { imya = "Bolshoi" }


pravda = const
lozh   = flip pravda


class PodobnoyeChislu m where
  sleduyusheeChisloPozhaluista :: m -> m
  predydusheeChisloPozhaluista :: m -> m
  nolLiEto :: m -> (a -> a -> a)
  nol :: m

  poschitayteVInteger :: m -> Integer
  poschitayteVInteger chislo
    | nolLiEto chislo True False = 0
    | otherwise = 1 + poschitayteVInteger (predydusheeChisloPozhaluista chislo)


instance PodobnoyeChislu Chislo where
  sleduyusheeChisloPozhaluista (Chislo { vladelec = vladelec, znachenie = znachenie }) = Chislo { vladelec = vladelec, znachenie = \f x -> znachenie f (f x) }
  predydusheeChisloPozhaluista (Chislo { vladelec = vladelec, znachenie = znachenie }) = Chislo { vladelec = vladelec, znachenie = \f x -> znachenie (\g h -> h (g f)) (const x) id }
  nolLiEto (Chislo { vladelec = vladelec, znachenie = znachenie }) = znachenie (const lozh) pravda
  nol = Chislo { vladelec = bratecYoba, znachenie = const id }


maksimumTrehChisel :: PodobnoyeChislu m => m -> m -> m -> String
maksimumTrehChisel a b c
  | nolLiEto a True False && nolLiEto b True False = "Tretye"
  | nolLiEto a True False && nolLiEto c True False = "Vtoroye"
  | nolLiEto b True False && nolLiEto c True False = "Pervoye"
  | otherwise = maksimumTrehChisel (predydusheeChisloPozhaluista a) (predydusheeChisloPozhaluista b) (predydusheeChisloPozhaluista c)


-- ALLOU, YOBA, MENYA SLYSHNO?
odin :: Chislo
odin    = sleduyusheeChisloPozhaluista nol
dva     = sleduyusheeChisloPozhaluista odin
chetyre = sleduyusheeChisloPozhaluista $ sleduyusheeChisloPozhaluista dva

main = putStrLn $ maksimumTrehChisel odin chetyre dva