Why None when calling the super().__add__() method?

Question

Python

There is a simple class

class C(int):
    def __add__(self, other):
        super(C, self).__add__(other)

a = C(1)
print(a+1)

I did not override the parent method, but instead of 2 I get -
None
Why?

Answer 1

if return is not specified in the function, then None is always returned by default

Answer 2

Thank you!