w | wW ww | ww ww ------+--------+--------+--------+-------- wW w | w W | WW Ww | Ww Ww w | wW wW | wW ww | W W | WW Ww | Ww Ww W | WW Ww | Ww WW | WW WW | Ww WW | Ww WW | WW WW | Ww WW | Ww WW | Ww WW | Ww | wW