*-----------* |5..|...|1..| |2.6|4.9|...| |..8|...|..2| |---+---+---| |..3|79.|4.1| |...|1.8|...| |8.7|.64|3..| |---+---+---| |7..|...|2..| |...|6.1|9.3| |..9|...|..8| *-----------*