Well your code currently does not compile for a different reason ... you have duplicate methods in your SubClass. You cannot define a method with the same name and argumnent list more than once in the same class.
However, if you only had 1 mymeth() method in your subclass ... then this question has been asked and answered before. Here is the
LINK
Another concept you need to understand is overriding vs hiding. Read this
ARTICLE for details.