class Animal {
    private String name;
    public Animal(String name) {
        this.name = name;
    }
    public String call() {
        return  name + working();
    }
    public abstract String working();
}

class Fly extends Animal {
    public Fly(String name) {
        super(name);
    }
    @Override public String working() {
        return "I am Flying";
    }
}

class Walk extends Animal {
    public Walk(String name) {
        super(name);
    }
    @Override public String working() {
        return "I am Walking";
    }
}

class Sing extends Animal {
    public Sing(String name) {
        super(name);
    }
    @Override public String working() {
        return "I am Singing";
    }
}

public class AnimalDemo {
    public static void main(String[] args) {
        Animal h = new Fly("1:");
        System.out.println(h.call());
        Animal c = new Walk("2:");
        System.out.println(c.call());
        System.out.println(new Sing("3:").call());
    }
}