???? ??? ??????? ???? ????? ??? ??? ?????? ??? ????? ?????????? ?? ????? ??????? ?????. ????? ????? ??? ?ficulties ???? ????? ????????? ? ??? ???? ?????? ???????. ?????? ?????? ????? ???? ???????? ?????? ????? ?????????? ???? ????. ?????? ????? ??? ???? ???? ????? ?????????? ?? ???????? ??????. ???? ?????? ????? ??? ????? ???????? ????????? ?