public class LinkedList {
    public int size = 0;
    public Element first;
    public Element last = null;


    static class Element {
        Element prev;
        Element next;
        Object value;

        Element (Object value) {
            this.value = value;
        }
    }

    public void add (Object o) {
        Element e = new Element(o);
        first.value = e.value;

        size++;
    }