abstract class Animal{
	public abstract void makeSound();
}
class Dog extends Animal implements Swimmable{
	@Override
	public void makeSound(){
		System.out.println("woof");
	}
	@Override
	public void swim(){
		System.out.println("dog is swimming");
	}
}
class Cat extends Animal{
	public void makeSound(){
		System.out.println("miao");
	}
}
interface Swimmable{
	void swim();
}
public class Main{
	public static void main(String[] args){
		Animal dog=new Dog();
		Animal cat=new Cat();
		Swimmable dog1=new Dog();
		dog.makeSound();
		dog1.swim();
		cat.makeSound();
	}
}