&otclass A {
  override def toString() : String = "a";
}

class B extends A {
  override def toString() : String = super.toString() + ;, b";
}

class C extends A {
  override def toString() : String = super.toString() + ", c";
}

class D extends A {
  override def toString() : String = super.toString() + ", d";
}


class BC extends B with C;
class BD extends B with D;
class CB extends C with B;
class CD extends C with D;
class DB extends D with B;
class DC extends D with C;

object Test {
  def main( args:Array[String] ): Unit = {
    System.out.println("BC " + (new BC));
    System.out.println("BD " + (new BD));
    System.out.println("CB " + (new CB));
    System.out.println("CD " + (new CD));
    System.out.println("DB " + (new DB));
    System.out.println("DC " + (new DC));
  }
}