Draw a level 0, 1, and 2 DFD for an online university registration system.

The system should enable each academic department's staff to examine the courses offered by their department, add and remove courses, and change the information about them (e.g., the maximum number of students permitted).

It should permit students to examine currently available courses, add and drop courses to and from their schedules, and examine the courses they are enrolled in.

Department staff should be able to print a variety of reports about the courses and the students enrolled in them.

The system should ensure that no student takes too many courses and that students who have any unpaid fees are not permitted to register. (Assume that a fees data store is maintained by the university's financial office, which the registration system accesses but does not change.)