public void push(int data)
        {
            StackIntNode oldLast = last;

            last      = new StackIntNode(data);
            last.Next = oldLast;
        }
        public int pop()
        {
            int value = last.Data;

            if (last.Next != null)
            {
                last = last.Next;
            }
            return(value);
        }
        public void print()
        {
            string line = "";

            curr = last;
            while (curr.Next != null)
            {
                line += curr + " ";
                curr  = curr.Next;
            }
            line += curr + " ";
            Console.WriteLine(line);
        }
 public StackIntLinkedList(int data)
 {
     last = new StackIntNode(data);
 }