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]● ==> J9   [ 4]○ ==> J8   [ 5]● ==> I7
[ 6]○ ==> H7   [ 7]● ==> J6   [ 8]○ ==> G9   [ 9]● ==> K5   [10]○ ==> L4
[11]● ==> K6   [12]○ ==> K7   [13]● ==> L6   [14]○ ==> I6   [15]● ==> M6
[16]○ ==> N6   [17]● ==> M7   [18]○ ==> N8   [19]● ==> M8   [20]○ ==> M5
[21]● ==> M9   [22]○ ==> M10  [23]● ==> J4   [24]○ ==> I3   [25]● ==> K3
[26]○ ==> G8   [27]● ==> K4   [28]○ ==> K2   [29]● ==> J5