??????? ??? ??? ??? ???? IOI997 ??? ?????? ???? ???????????? ??????? ????? ????????? ??????. ???????????? ??? ??????????? ???????? ???? 24??????? ???? ??????????? ??? ??? ????? ??????????????????????? ????? ?????? ??????????????? ??????????? ?????? ??? ioi997 . ????????????????? ?????? pc. ????? ?????? ??? ????????? ???! ??? ????? ioi99