class Operation:

def Sum(self,n1,n2):

SumResult=n1+n2

print("Sum=",SumResult)

def Sub(self,n1,n2):

SubResult=n1-n2

print("Sub=",SubResult)

class OperationWithMul(Operation):

def Mul(self,n1,n2):

MulResult=n1*n2

print("Mul=",MulResult)

def main():

#OP=Operation()

#OP.Sub(4,2)

#OP.Sum(10,15)

OpMul=OperationWithMul();

OpMul.Sub(4,2)

OpMul.Sum(10,15)

OpMul.Mul(10,2)

if __name__ == '__main__':main()