Abstract interfaces

Question

I have no idea why this code is not printing anything.
class Main {
public static void main(String[] args) {
Animal dog = new Dog();
Animal cat = new Cat();

dog.swim();
dog.play();
cat.swim();
cat.play();

}
}

interface Swimmer {
void swim();
}

interface Player {
void play();
}

//implement the Swimmer and the Player interfaces
abstract class Animal implements Swimmer,Player{
}

class Dog extends Animal {
//Override the swim() and the play() methods
public void swim(){
System.out.println("Dog is swimming");
}
public void play(){
System.out.println("Dog is playing");

}
}

class Cat extends Animal {
//Override the swim() and the play() methods
public void swim(){
System.out.println("Cat is swimming");
}
public void play(){
System.out.println("Cat is playing");
}

Answer 1

Cat class not closed. Missing } at end.

Answer 2

Thank you so much