?????????????, ?????????????, ???????, ??????????, ?????????? ??? ???? ?????.????????? ??? ????????? ?????? - ????????? ????????? (???? ????? ??? ???? ???????????)?? ??? ??? ????? ????????? ??? ????? ????????? ??? ? ?? ????? ????????????? ???????????? ?????????? ?????? ?????????? ????? structure??????????? ????? ?????????????? ?????????-???????????