lol.cs

namespace ConsoleApplication3
{
    class Program
    {
        static void Main(string[] args)
        {
            //B b = new B();
            //b.print();
            //b.hi();
        

            Console.ReadLine();
        }   
    }

    public abstract class A : B
    {
        protected int a1;
        public int A1
        {
            get { return a1; }
            set { a1 = value; }
        }
        public A()
        {
            a1 = 121;
        }
        public void hi() { Console.WriteLine("hi"); }

        //virtual 

    }

    public class B 
    {
        
    }
}