o3.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)

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

#trying to add two class objects,it will raise TypeError.Because compiler doesn't know how to add objects s1 and s2
print (s1+s2)   #Output:TypeError: unsupported operand type(s) for +: 'Student' and 'Student'