public static Node Parse(string nodes)
        {
            Node head = null;
            List<string> StringNumbers = nodes.Split(' ').ToList();

            for(int i=0;i<StringNumbers.Count();i++)
            {
                if(int.TryParse(StringNumbers[i], out int s)==true)
                {
                    head = new Node(s, head.Next);
                }
            }
            return head;
        }
        //  Assert.AreEqual(new Node(1, new Node(2, new Node(3))), Kata.Parse("1 -> 2 -> 3 -> null"));
        //Assert.AreEqual(new Node(0, new Node(1, new Node(4, new Node(9, new Node(16))))), Kata.Parse("0 -> 1 -> 4 -> 9 -> 16 -> null"));
        //Assert.AreEqual(null, Kata.Parse("null"));
        public class Node : Object
        {
            public int Data;
            public Node Next;

            public Node(int data, Node next = null)
            {
                this.Data = data;
                this.Next = next;
            }

            public override bool Equals(Object obj)
            {
                // Check for null values and compare run-time types.
                if (obj == null || GetType() != obj.GetType()) { return false; }

                return this.ToString() == obj.ToString();
            }

            public override string ToString()
            {
                List<int> result = new List<int>();
                Node curr = this;

                while (curr != null)
                {
                    result.Add(curr.Data);
                    curr = curr.Next;
                }

                return String.Join(" -> ", result) + " -> null";
            }
        }