class University:
	def __init__(self,name):
		self.name = name
		self.courses = []
		self.students = []
	
	def __str__(self):
		return self.name
		
	def addCourse(self, course):
		self.courses.append(course)
	
	def addStudent(self,student):
		self.students.append(student)
		
	def registerStudentForCourse(self,student,course):
		student.addCourse(course)
		course.addStudent(student)
		
	def printCourses(self):
		for c in self.courses:
			print(c)
	
	def printStudents(self):
		for s in self.students:
			print(s)

class Course:
	# A couse can be created with a number, name, description, prerequisit, and grading option
	def __init__(self, number, name, desc):
		self.number = number
		self.name = name
		self.desc = desc
		# Every course starts off with an empty list of students
		self.students = []
	# This tells python to print the name and description for the Course object
	def __str__(self):
		return self.name + " - " + self.desc
	# This methods takes a Student object and adds it to the list of students
	def addStudent(self, student):
		self.students.append(student)
	def printStudents(self):
		for s in self.students:
			print(s,)

class Student:
	def __init__(self, name, id, schedule=[]):
		self.name = name
		self.id = id
		self.schedule = schedule
	def addCourse(self, course):
		self.schedule.append(course)
	def __str__(self):
		return self.name	
	
cal = University("University of California Berkeley")	
i90 = Course(90,"Info 90", "Python Programming")
i202 = Course(202,"Info 202", "Info Org and Retreival")
ariel = Student("Ariel","03343")
gabriel = Student("Gabriel","44543")
irene = Student("Irene", "544348")

cal.addCourse(i90)
cal.addCourse(i202)
cal.addStudent(ariel)
cal.addStudent(gabriel)
cal.addStudent(irene)
cal.registerStudentForCourse(ariel,i90)
cal.registerStudentForCourse(gabriel,i90)
cal.registerStudentForCourse(ariel,i202)
cal.registerStudentForCourse(gabriel,i202)
cal.registerStudentForCourse(irene,i202)
print("Courses at " + str(cal))
cal.printCourses()
print();
print("Students in " + str(i90))
i90.printStudents()