???? ??? ????? ?? ?????? ?? heaps ?? ?????? ????????? ???? ????? ????? ?????. ????? ????? ??? ???? ????? ????? ?? ?????? ?????? ???????? ?-???? ??- ???? ?????????. ????? ???????: ???? ?????? ?[: ???????. ?????:??? ????: ??????? ???????? ????? ????* ?-?????[ ????]. ????? ?????? :??????? ???????:??????? ??????? ??-\} ???? ??? {????? ?