abstract class Animal {
    public abstract void makeSound();
}
interface Swimmable {
    void swim();
}
class Dog extends Animal implements Swimmable {
    @Override
    public void makeSound() {
        System.out.println("汪汪汪");
    }
    @Override
    public void swim() {
        System.out.println("狗会游泳");
    }
}
class Cat extends Animal {
    @Override
    public void makeSound() {
        System.out.println("喵喵喵");
    }
}
public class AnimalTest {
    public static void main(String[] args) {
        Animal dog = new Dog();
        Animal cat = new Cat();
        System.out.println("叫声");
        dog.makeSound();
        cat.makeSound();
        System.out.println("游泳");
        if (dog instanceof Swimmable) {
            ((Swimmable) dog).swim();
        } else {
            System.out.println("不会游泳");
        }
        if (cat instanceof Swimmable) {
            ((Swimmable) cat).swim();
        } else {
            System.out.println("不会游泳");
        }
    }
}