Your task is to model the system that is capable of managing students and staff members as a part of student system.

Students should have some programs assigned to them as well as personal information about their studies' status.

Staff members can maintain some classes as well as have some set of publications that they've published.

As a part of this task you should:

• create your own class hierarchy from scratch for this problem (as we did on exercises)
• provide at least 2 examples of overriding in your class model:
  • the first using reference to super in its implementation
  • the second completely overriding parent's method (which may be abstract)
• have a look how Java Map<String, Person> work (and use probably HashMap<String, Person>) and use it in system
• have a look how Java Set<Publication> and use it in staff member
• work with static variables to generate identifiers for consecutive people in the world (you can assume that people get natural numbers in the order of their creation) - create PersonFactory class with only static methods that will be responsible for creating students and staff members
• play with your model in Main class a little and show how your implementation works