public Integer kthToLast(int k)
	{
		if (k <= 0 || head == null)
			throw new IllegalArgumentException("There is no such element.");
		Node runner = head;
		Node pointer = head;
		int counter = 1;
		for (; runner.next != null && counter < k; counter++)
		{
			runner = runner.next;
		}
		if (counter < k && runner.next == null)
			return null;
		while (runner.next != null)
		{
			runner = runner.next;
			pointer = pointer.next;
		}
		return pointer.data;
	}