mc23.hs:9:29:
    Couldn't match type ‘[a0]’ with ‘[a] -> m a’
    Expected type: (a -> b) -> [a] -> m a
      Actual type: [a0] -> [a0]
    Relevant bindings include z :: m b (bound at mc23.hs:9:1)
    Possible cause: ‘take’ is applied to too many arguments
    In the expression: take 5
    In a stmt of a monad comprehension: then take 5 by x