public static List <HotelRoom> GetAviableRooms(List <string> dates) { List <long> reservationIds = ServicesHotelRoomReservedDate.GetReservationIds(dates); List <long> reservedHotelRoomId = ServicesReservation.GetReservedHotelRoomIds(reservationIds); return(ServicesHotelRoom.GetAviableHotelRooms(reservedHotelRoomId)); }