How To Create A C# Program Without Create Object Calling Method

using System;



    class usingstatic
    {
    public  static void Add()
    {
        int a = 10;
        int b = 10;
        int c=a+b;
        Console.WriteLine(c);
        Console.ReadKey();
    }
    class Demo
    {
        static void Main()
        {

               Add();
           }

    }
}