class A
     {
          public A(){
                PrintFields();
           }
          public virtual void PrintFields(){}
      }
    class B : A
    {
        int x = 1;
        int y;
        public B()
        {
            y = -1;
        }
        public override void PrintFields()
        {
            Console.WriteLine("x={0},y={1}", x, y);
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            B b = new B();
            b.PrintFields();
            Console.ReadKey();
        }
    }