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