class List {

  private int data;
  private List next;

  //public int N;
  //public final int x = N;

  public List() {
    //x = 9;
    data = 0;
    next = null;
  }

  public int getHead() {
    return data;
  }

  public List getTail() {
    return next;
  }

  public void setHead(int data) {
    this.data = data;
  }

  public int getLength() {
    if(next == null) { return 1; }
    else {
      return 1+next.getLength();
    }
  }

  public int getLast() {
    if(next == null) { return data; }
    else { return next.getLast(); }
  }

  public List addToFront(int data) {
    List l1 = new List();
    l1.data = data;
    l1.next = this;
    return l1;
  }

  public void print() {
    if(next == null) { System.out.println(data+","); }
    else {
      System.out.print(data+",");
      next.print();
    }
  }

  public void reverse_print() {
    if(next == null) { System.out.println(data+","); }
    else {
      next.reverse_print();
      System.out.println(data+",");
    }
  }

  public static void main(String[] args) {
    List l1 = new List();
    l1.setHead(0);
    l1 = l1.addToFront(1);
    l1 = l1.addToFront(2);

    l1.print();
    l1.reverse_print();
  }

} // End class List