A B C D E F G H I J K L M N O
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  1 └┴┴┴┴┴┴┴┴┴┴┴┴┴┘
[ 1]● ==> H8   [ 2]○ ==> I9   [ 3]● ==> J8   [ 4]○ ==> I8   [ 5]● ==> I7
[ 6]○ ==> H6   [ 7]● ==> J6   [ 8]○ ==> G9   [ 9]● ==> K7   [10]○ ==> J9
[11]● ==> K9   [12]○ ==> H7   [13]● ==> K10  [14]○ ==> K6   [15]● ==> H9
[16]○ ==> G8   [17]● ==> G6   [18]○ ==> F9   [19]● ==> E10  [20]○ ==> G10
[21]● ==> G11  [22]○ ==> I10  [23]● ==> K8   [24]○ ==> K11  [25]● ==> I12
[26]○ ==> D7   [27]● ==> E8   [28]○ ==> J5   [29]● ==> I6   [30]○ ==> H3
[31]● ==> L7