class A:
    def m1(self):
        return "m1 von A "

    def m2(self):
        return "m2 von A "

    def m3(self):
        return "m3 von A "

class B(A):
    def m1(self):
        return "m1 von B "

class C(B):
    def m3(self):
        return "m3 von C "


######
a = A()
b = B()
c = C()
a2 = A()

q = ''

BLOCK_1234

print(q)