?????? ??????, ??? ?? ??, ?? ?? ? ??? ??? ???? ???, ? ???? ?? ????? ??? ???? ?? ??? ?? ???? ????.??? ?? ??? ???? ???? ???, ?? ??? ???? ???? ????. ??? ?? ??? ???? ?? ??? ??? ??? ??? ?? ???? ??????.A "box technique" can be applied occasionally, when the geometry of the unfilled white cells at any presented phase of fixing lends itself to it: by summi