A B C D E F G H I J K L M N O      [ 1]● ==> H8   [ 2]○ ==> I9
 15 ┌┬┬┬┬┬┬┬┬┬┬┬┬┬┐      [ 3]● ==> I6   [ 4]○ ==> H7
 14 ├┼┼┼┼┼┼┼┼┼┼┼┼┼┤      [ 5]● ==> J7   [ 6]○ ==> J6
 13 ├┼┼┼┼┼┼┼┼┼┼┼┼┼┤      [ 7]● ==> H5   [ 8]○ ==> G4
 12 ├┼┼┼┼┼┼┼┼┼┼┼┼┼┤      [ 9]● ==> I5   [10]○ ==> I4
 11 ├┼┼┼┼┼┼┼┼┼┼┼┼┼┤      [11]● ==> K5   [12]○ ==> J5
 10 ├┼┼┼┼┼┼┼┼┼┼┼┼┼┤      [13]● ==> K6   [14]○ ==> K8
  9 ├┼┼┼┼┼┼┼○┼┼┼┼┼┤      [15]● ==> K3   [16]○ ==> K4
  8 ├┼┼┼┼┼┼●┼┼○┼┼┼┤      [17]● ==> J4   [18]○ ==> L2
  7 ├┼┼┼┼┼┼○┼●┼┼○┼┤      [19]● ==> L6   [20]○ ==> M7
  6 ├┼┼┼┼┼┼┼●○●●┼┼┤      [21]● ==> L5   [22]○ ==> M4
  5 ├┼┼┼┼┼●●●○●●┼┼┤      [23]● ==> G5
  4 ├┼┼┼┼┼○┼○●○┼○┼┤
  3 ├┼┼┼┼┼┼┼┼┼●┼┼┼┤
  2 ├┼┼┼┼┼┼┼┼┼┼○┼┼┤
  1 └┴┴┴┴┴┴┴┴┴┴┴┴┴┘