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]○ ==> H9   [ 3]● ==> J10  [ 4]○ ==> I9   [ 5]● ==> I8
[ 6]○ ==> J8   [ 7]● ==> G9   [ 8]○ ==> F10  [ 9]● ==> H10  [10]○ ==> F8
[11]● ==> J11  [12]○ ==> I11  [13]● ==> K10  [14]○ ==> I10  [15]● ==> I12
[16]○ ==> L9   [17]● ==> J9   [18]○ ==> L11  [19]● ==> F9   [20]○ ==> G12
[21]● ==> G6   [22]○ ==> H7   [23]● ==> G7   [24]○ ==> G8   [25]● ==> E6
[26]○ ==> F6