class A:
def __init__(self, v):
self.v = v
def __add__(self, o):
if isinstance(o, A):
return A(self.v + o.v)
return A(self.v + o)
def __radd__(self, o):
def __repr__(self):
return "A({})".format(self.v)
print(A(3) + 1)
print(2 + A(5))