给定Python代码如下：

class Num:
    def __init__(self,val):
        self.Value = val
    def __add__(self,other):
        return self.Value + other.Value
    def add(self,other):
        return self.Value + other.Value

a = Num(10)
print(a + Num(20), Num(20).__add__(a), a.add(Num(20)))
print(a)