newtype PrimeNumber = PrimeNumber Int deriving (Show)

isPrime :: Int -> Bool
isPrime k = if k > 1 then null [x | x <- [2 .. k - 1], k `mod` x == 0] else False

mkPrime :: Int -> Maybe PrimeNumber
mkPrime i = if isPrime i then Just (PrimeNumber i) else Nothing

printPrime :: PrimeNumber -> IO ()
printPrime p = print p

addPrimes :: PrimeNumber -> PrimeNumber -> PrimeNumber
addPrimes (PrimeNumber p1) (PrimeNumber p2) = PrimeNumber (p1 + p2)

main :: IO ()
main = do
  let number = 2
  case mkPrime number of
    Just p -> do
      printPrime p
      let primesAdded = addPrimes p p
       in putStrLn ("primesAdded: " <> show primesAdded)
    Nothing -> putStrLn "number was not prime"