class X {
    private int x;
    public X(int x) {
	System.out.println("Skapar en X(" + x + ").");
	this.x = x;
    }
    public X() {
	this(0);
	System.out.println("Skapar en X().");
    }
    public void f() {
	System.out.println("X.f");
    }
} // X

class XYZ extends X {
    private int y;
    private int z;
    public XYZ(int x, int y, int z) {
	super(x);
	System.out.println("Skapar en XYZ(" + x + ", " + y + ", " + z + ").");
	this.y = y;
	this.z = z;
    }
    public XYZ(int y, int z) {
	super();
	System.out.println("Skapar en XYZ(" + y + ", " + z + ").");
	this.y = y;
	this.z = z;
    }
    public void f() {
	System.out.println("XYZ.f");
    }
} // X

public class Uppgift3 {
    X x;
    public Uppgift3() {
	x = new XYZ(1, 2, 3);
    }
    public static void main(String [] args) {
	Uppgift3 u = new Uppgift3();
	X x1 = new X();
	X x2 = new XYZ(4, 5, 6);
	XYZ xyz = new XYZ(17, 19);
	u.f(x1);
	g(x2);
    } // main
    public void f(X x) {
	System.out.println("Uppgift3.f");
	x.f();
	this.x.f();
    }
    static public void g(X x) {
	System.out.println("Uppgift3.g");	
	x.f();
    }
} // Uppgift3