class PolyC {
    public String greeting() { return "Hello"; }
}
public class PolyTestC {
    public void main(String[] args) {
        Object x = new PolyC();
        if (x instanceof PolyC)
            System.out.print(((PolyC) x).greeting()+" World!\n");
        else
            System.out.print("Sorry: no cast possible!\n");
    }
}