static void Main()         {             int[] array = { 1, 2, 3, 4, 5, 6, 7 };             MoveNumberArrayToEnd(array, 3);         }         static void MoveNumberArrayToEnd<T>(IList<T> arrayList, int num)         {             if (arrayList.Count < = 0 || arrayList.Count < num)             {                 throw new RankException();             }             var query = (from number in arrayList                          orderby number descending                          select number).Take(arrayList.Count - num).Concat(arrayList.Take(num));             query.ToList().ForEach(q => Console.WriteLine("{0}", q));         }