public class Inheritance {
    public static int main() {
        Dog dog = new Dog();
        dog.age = 5;

        dog.speak();
        dog.showAge();

        return 0;
    }
}

class Animal {
    int age;

    void speak() {
        System.out.println("Animal speaks");
    }

    void showAge() {
        System.out.println(this.age);
    }
}

class Dog extends Animal {
    void speak() {
        System.out.println("Woof!");
    }
}