public class School {
  public static void main(String[] args) {

    ClassRoom classroom1 = new ClassRoom("A100");
    ClassRoom classroom2 = new ClassRoom("A101");
    ClassRoom classroom3 = new ClassRoom("B05");

    classroom1.addRadio(Input.readInputLine());
    classroom1.addTelev(Input.readInputLine());
    classroom3.addRadio(Input.readInputLine());

    classroom1.removeRadio();

    System.out.println(Device.getCount() + " devices");
  }
}

class ClassRoom {
  String id;
  Device radio, telev;

  ClassRoom (String code) { id = code; }

  void addRadio(String desc) { radio = new Device(desc); }

  void addTelev(String desc) { telev = new Device(desc); }

  void removeRadio () {radio.remove(); radio = null; }

  void removeTelev () {telev.remove(); telev = null; }

}

class Device {
  static int count = 0;
  String description;

  Device (String desc) {
    description = desc; count++;
  }

  void remove () {
    System.out.println("Removing " + description);
    count--;
  }

  static int getCount () { return count; }
  
}