public boolean insert(E e){
		boolean added = false;
		if(first == null){
			first = new LinkedNode<E>(e);
			added = true;
		}else{
			LinkedNode<E> node = first;
			LinkedNode<E> pre = null;
			while(node != null){
				if(node.value.compareTo(e) == 0){
					return false;
				}
				if(node.value.compareTo(e) > 0){
					if(pre == null){
						first = new LinkedNode<E>(e);
						first.next = node;
					}else{
						pre.next = new LinkedNode<E>(e);
						pre.next.next = node;
					}
					added = true;
					break;
				}else{
					pre = node;
					node = node.next;
				}
			}
			if(!added){
				pre.next = new LinkedNode<E>(e);
			}
		}
		size++;
		return added;
	}