Simple Queue

 public class Queue
    {
        public List<int> Space = new List<int>();

        // Enqueue Operation for Queue item
        public void EnQueue(int value)
        {
            Space.Add(value);
        }

        // Dequeue Operation for Queue item
        public int DeQueue()
        {
            if (Space.Count > 0)
            {
                var value = Space[0];

                for (int i = 0; i < Space.Count - 1; i++)
                {
                    Space[i] = Space[i + 1];
                }

                Space.RemoveAt(Space.Count - 1);
                return value;
            }
            else
            {                
                return -1;
            }
        }
    }