class A1{
    public void tell1(){
        System.out.println("A1 -- tell1");
    }
}

class B1 extends A1{
    public void tell1(){
        System.out.println("B1 -- tell2");
    }
}

class C1 extends A1{
    public void tell1(){
        System.out.println("C1 -- tell3");
    }
}

public class PolDemo02 {

    public static void main(String[] args) {
        say(new B1());
        say(new C1());
    }
    
    public static void say(A1 a){
        a.tell1();
    }
}