.5 балла)
maybeP :: Parser a -> Parser (Maybe a)
maybeP p = Just <$> (just *> char ' ' *> p) <|> nothing *> pure Nothing

-- (0.5 
maybeP :: Parser a -> Parser (Maybe a)
maybeP p = Just <$> (just *> char ' ' *> p) <|> nothing *> pure Nothing
maybeP p = Just <$> (just *> char ' ' *> p) <|> nothing *> pure Nothing