How to compare two collections and get same element(System.Collection.Generic.List)

 List<String> NewList = null;
 List<String> student = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 };

 List<String> staff = { 5, 26, 8,  20, 34, 15 };

foreach (String mbr in student )  {
if(staff.Contains(mbr) {
                 NewList.Add(mbr);
      }
}

In this NewList has the values 5,8,15 from Student List.

How to delete Last record from SQL Server

Id- ColumnName

delete from tableName where Id in (select top 1 Id from tbaleName order by Id desc)