Construct an ER diagram for the Hogwarts School of Witchcraft and Wizardry. Students have first name, last name, student id, and a class year. There are Houses with house names, a motto, a mascot, and a house ghost. Each student has a house assignment. Professors have a professor id, first name and last name. A professor is a head of some house. Professors teach Courses which have a course id, name, description, required textbook and required equipment. A student can enroll in a course.