?????? ???? ????? ?????? ???? fluctuations ????? ?? ???? ????? ???? ??? ???. ????? ???? ????? ???? ????? ???? ?? ??? ?? ???? ?? ????? ?????? ????? ?? ????? ???? ???? ???? ????? ???? ????? ???? ?? ??? ?? ?????/????/ ????? ??????/??????/????? ???? ???. ????? ????? ????: ????? ?? ?????? ????? ????