class Dog():
    def run(self):
        print('dog : run()')

    def walk(self):
        print('dog : walk()')


class Cat():
    def run(self):
        print('cat : run()')

    def walk(self):
        print('cat : walk()')


class Horse():
    def run(self):
        print('horse : run()')

    def walk(self):
        print('horse : walk()')