internal class Program
{
    private static void Main(string[] args)
    {
        var mycls = new MyClass();
        mycls.Name = "철수";
        mycls.Run(100);
        //mycls._id = 100; //에러
        //mycls.Execute() //에러
    }


    internal class MyClass
    {
        private int _id = 0;

        public string Name { get; set; }

        public void Run(int id) { }

        protected void Execute() { }
    }

}