class Animal {

  void makeSound() {

    System.out.println("Animal sound");

  }

}

​

class Dog extends Animal {

  @Override

  void makeSound() {

    System.out.println("Woof!");

  }

}

​

public class Main {

  public static void main(String[] args) {

    Animal myDog = new Dog();

    myDog.makeSound();

  }

}

​