Resolving Diamond Inheritance within Python Classes

Consider the following python code:

class Parent(object):
    def __init__(self, name, serial_number):
        self.name = name
        self.serial_number = serial_number


class ChildA(Parent):
    def __init__(self, name, serial_number):
        self.name = name
        self.serial_number = serial_number
        super(ChildA, self).__init__(name = self.name, serial_number = self.serial_number)

    def speak(self):
        print("I am from Child A")


class ChildB(Parent):
    def __init__(self, name, serial_number):
        self.name = name
        self.serial_number = serial_number
        super(ChildB, self).__init__(name = self.name, serial_number = self.serial_number)

    def speak(self):
        print("I am from Child B")


class GrandChild(ChildA, ChildB):
    def __init__(self, a_name, b_name, a_serial_number, b_serial_number):
        self.a_name = a_name
        self.b_name = b_name
        self.a_serial_number = a_serial_number
        self.b_serial_number = b_serial_number
        super(GrandChild, self).__init_( something )

When running the super function in GrandChild, what is the proper way to format the __init__ arguments so that ChildA and ChildB both get the correct arguments?

Also how do you access the two different versions of the speak method (ChildA's version and ChildB's version) from within the GrandChild class?