A B C D E F G H I J K L M N O   [ 1]● ==> H8   [ 2]○ ==> H9
 15 ┌┬┬┬┬┬┬┬┬┬┬┬┬┬┐   [ 3]● ==> H6   [ 4]○ ==> I10
 14 ├┼┼┼┼┼┼┼┼┼┼┼┼┼┤   [ 5]● ==> I6   [ 6]○ ==> I9
 13 ├┼┼┼┼┼┼┼┼┼┼┼┼┼┤   [ 7]● ==> G9   [ 8]○ ==> G8
 12 ├┼┼┼┼┼┼┼┼┼┼┼┼┼┤   [ 9]● ==> J11  [10]○ ==> I7
 11 ├┼┼┼┼┼┼┼┼●┼┼┼┼┤   [11]● ==> I8   [12]○ ==> J9
 10 ├┼┼┼┼┼┼┼○┼┼┼┼┼┤   [13]● ==> K8   [14]○ ==> K7
  9 ├┼┼┼┼┼●○○○●○┼┼┤   [15]● ==> J7   [16]○ ==> L9
  8 ├┼┼┼┼┼○●●┼●○┼┼┤   [17]● ==> K9   [18]○ ==> H5
  7 ├┼┼┼┼┼┼┼○●○┼┼┼┤   [19]● ==> L6   [20]○ ==> L8
  6 ├┼┼┼┼┼┼●●┼┼●┼┼┤   [21]● ==> J4   [22]○ ==> J5
  5 ├┼┼┼┼┼┼○┼○┼┼┼┼┤
  4 ├┼┼┼┼┼┼┼┼●┼┼┼┼┤
  3 ├┼┼┼┼┼┼┼┼┼┼┼┼┼┤
  2 ├┼┼┼┼┼┼┼┼┼┼┼┼┼┤
  1 └┴┴┴┴┴┴┴┴┴┴┴┴┴┘