using System;

public class Program

{

    public static void Main()

    {

        var kitten = new Kitten();

        kitten.Name = "Vasya";

        kitten.Name = null;

        Console.WriteLine(kitten.Name);

    }

    public class Kitten

    {

        private string name;

        public string Name

        {

            get { return name; }

            set 

            {

                if(!string.IsNullOrEmpty(value))

                {

                    name = value;

                }

            }

        }   

    }

}