A B C D E F G H I J K L M N O
 15 ┌┬┬┬┬┬┬┬┬┬┬┬┬┬┐ 
 14 ├┼┼┼┼┼┼┼┼┼┼┼┼┼┤ 
 13 ├┼┼┼┼┼┼┼┼┼┼┼┼┼┤ 
 12 ├┼┼┼┼┼┼○┼┼┼┼┼┼┤ 
 11 ├┼┼┼┼┼●●●○┼┼┼┼┤ 
 10 ├┼┼┼┼┼○●○┼┼┼┼┼┤ 
  9 ├┼┼┼┼┼○●○●┼┼┼┼┤ 
  8 ├┼┼┼┼┼○●○┼●┼┼┼┤ 
  7 ├┼┼┼┼┼●○┼●┼●┼┼┤ 
  6 ├┼┼┼┼┼○┼●●┼○┼┼┤ 
  5 ├┼┼┼┼○●○○○○●┼┼┤ 
  4 ├┼┼┼●┼┼┼┼┼┼┼┼┼┤ 
  3 ├┼┼┼┼┼┼┼┼┼┼┼┼┼┤ 
  2 ├┼┼┼┼┼┼┼┼┼┼┼┼┼┤ 
  1 └┴┴┴┴┴┴┴┴┴┴┴┴┴┘ 

[ 1]● ==> H8   [ 2]○ ==> I9   [ 3]● ==> I6   [ 4]○ ==> G9   [ 5]● ==> J7
[ 6]○ ==> G8   [ 7]● ==> K8   [ 8]○ ==> H5   [ 9]● ==> H9   [10]○ ==> G10
[11]● ==> G11  [12]○ ==> G6   [13]● ==> G7   [14]○ ==> I8   [15]● ==> H10
[16]○ ==> H7   [17]● ==> H11  [18]○ ==> H12  [19]● ==> J9   [20]○ ==> I10
[21]● ==> I11  [22]○ ==> J11  [23]● ==> J6   [24]○ ==> J5   [25]● ==> L7
[26]○ ==> F5   [27]● ==> E4   [28]○ ==> I5   [29]● ==> G5   [30]○ ==> K5
[31]● ==> L5   [32]○ ==> L6