SharePoint Destination

using System; using System.CodeDom.Compiler ; namespace csharpoops {                     abstract class test1                 {                                   public abstract int Fun(int a,int b);                                       public int Checking(int d,int e)                                   {                                                    d=3346;                                                  e=123;                                                return d-e;                                     }                   }                  //Interface Example                    public interface Icalc                 {                                     int fn_add(int x, int y );                 }                  //Structure Example                     struct employee                 {                                     public string name;