

class  Student:
    def __init__(self,name,school):
        self.name = name
        self.school = school
        self.marks = []

    def average(self):
        return sum(self.marks) / len(self.marks)

    @classmethod
    def friend(cls,origin,friend_name,salary):
        return cls(friend_name,origin.school,salary)

class WorkingStudent(Student):
    def __init__(self,name,school,salary):
        super().__init__(name,school)
        self.salary = salary

anna = WorkingStudent('Anna','Oxford' , 19.23)
print(anna.salary)

friend = WorkingStudent.friend(anna , 'Greg', 20.35)
print(friend.name)
print(friend.school)
print(friend.salary)
