????????????????????????????????????? ??????? ??? ????? ???? ?????? ??? ??? ???? ?????? ??? ?????????? ??? ???? ????? ?????? ??????????????? ??????????? ?????????? ????? ?????????????? ????? ?????? a ??? ??? ??? ??????? ???? ? ???? ????????? ??? ??????????? ????? ?????????? ??? ????? ??????????? ???? ???? ??????? ?????? ???? ???? ??? ???????? ?????