o4.py

class Student:
    def __init__(self,name,rollno,age):
        self.name=name
        self.rollno=rollno
        self.age=age
    def __str__(self):
        return "{}-{}-{}".format(self.name,self.rollno,self.age)
    def __add__(self,other):
        return (self.age+other.age)
      

s1=Student("karthi",12,7)
s2=Student("Sarvesh",15,3) 

#when trying to add two class objects,magic method __add__() is invoked.
#It will add age attribute of two Student objects according to the behavior mentioned in the method __add__()
print (s1+s2)#Output: 10