class Punkt2D(var x: Double = 0, var y: Double = 0) {
   override def toString = "(x,y) = (" + x + ", " + y +")"
}

class Punkt3D(x: Double, y: Double, var z: Double) extends Punkt2D {
   override def toString = "("+x+", "+y+", "+z+")"
}

object Punkt3D extends Application {
   def apply(x: Double, y: Double, z: Double) = new Punkt3D(x,y,z)
   println(Punkt3D( 1, 2, 3))
}