from abc import ABC,abstractmethod
class polygon(ABC):
    @abstractmethod 
    def no_of_sides(self):
        pass
class triangle(polygon):
    def no_of_sides(self):
        print('I have 3 sides')
class pentagon(polygon):
    def no_of_sides(self):
        print('I have 5 sides')
class hexagon(polygon):
    def no_of_sides(self):
        print('I have 6 sides')
class quadrilateral(polygon):
    def no_of_sides(self):
        print('I have 4 sides')
t=triangle()
t.no_of_sides()
p=pentagon()
p.no_of_sides()
h=hexagon()
h.no_of_sides()
q=quadrilateral()
q.no_of_sides()