A B C D E F G H I J K L M N O
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  1 └┴┴┴┴┴┴┴┴┴┴┴┴┴┘ 

[ 1]● ==> H8   [ 2]○ ==> H9   [ 3]● ==> H6   [ 4]○ ==> I9   [ 5]● ==> I7
[ 6]○ ==> J8   [ 7]● ==> G9   [ 8]○ ==> J6   [ 9]● ==> H10  [10]○ ==> I11
[11]● ==> F8   [12]○ ==> J9   [13]● ==> J10  [14]○ ==> I10  [15]● ==> I8
[16]○ ==> J11  [17]● ==> G8   [18]○ ==> E8   [19]● ==> F10  [20]○ ==> E11
[21]● ==> F9   [22]○ ==> F7   [23]● ==> I6   [24]○ ==> H7   [25]● ==> I5
[26]○ ==> I4