public class Numbers
    {
        public int ControlCount;
        static Numbers number;
        public static Numbers numbers
        {
            get
            {
                if (number == null)
                {
                    number = new Numbers();
                }
                return Numbers.number;
            }
            set
            {
                number = value;
            }
        }
    }

     class Program
    {
        static void Main(string[] args)
        {
            var a = Numbers.numbers;
            a.ControlCount = 9;
            Console.WriteLine(a.ControlCount);
            a.ControlCount++;
            Console.WriteLine(a.ControlCount);

            var b = Numbers.numbers ;
            Console.WriteLine(b.ControlCount);
            b.ControlCount++;
            Console.WriteLine(b.ControlCount);
            Console.ReadLine();
        }
    }