Some explanation about constructor in c#

[firoz.raj]

Can anyone tell me ???Why the following code is not working ?let me know some idea.

using System;
using System.Collections.Generic;
using System.Text;

namespace Example9
{
    class Program
    {
        static void Main(string[] args)
         {
           Public String Program();
           {
               Console.WriteLine("I am a Constructor");

               return;
           }
             
        }
    }
}