[5] Please draw an EERD based on following description. Suppose that you are asked to model the human resources in a university. They consider three types of people: employees, student and alumnus. Employee has SSN, name, address, gender, date of birth, salary, and date of hire. And there is no other type of personnel in this university. Some employees are also alumnus. And also some students are also employees. Students have SSN, name, address, gender, date of birth, and major department. Alumni have SSN, name, address, gender, date of birth, degree, and degree received date. Employees can be partitioned into two sub types: faculty and staff. Faculty has the specific attribute rank, while staff has the specific attribute position. An employee can not be both faculty and staff at the same time. Two subtypes are also defined for students: graduate student and undergraduate student. Undergraduate student has the attribute class_standing, while graduate student has the attribute test_score. A student can not be both graduate and undergraduate student. Every graduate student is assigned to a faculty and a faculty can have many graduate students.