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

[ 1]● ==> H8   [ 2]○ ==> I8   [ 3]● ==> J6   [ 4]○ ==> I7   [ 5]● ==> J7
[ 6]○ ==> H6   [ 7]● ==> I9   [ 8]○ ==> J8   [ 9]● ==> K9   [10]○ ==> L9
[11]● ==> J10  [12]○ ==> K11  [13]● ==> H10  [14]○ ==> H9   [15]● ==> L8
[16]○ ==> I11  [17]● ==> K7   [18]○ ==> I5   [19]● ==> I10  [20]○ ==> K10
[21]● ==> M7   [22]○ ==> N6   [23]● ==> M8   [24]○ ==> M9   [25]● ==> L7
[26]○ ==> N7   [27]● ==> K8   [28]○ ==> I6   [29]● ==> I4   [30]○ ==> M6
[31]● ==> N8