bb b b
b b  bb
 b       b
 bbb b bbb
 b bbbb
 bbbb    b
     b b
 b b b  b

     bb

false
bb b b
b b  bb
xb       b
xbbb b bbb
xb bbbbxxx
xbbbbxxxxb
xxxxxbxbxx
xbxbxbxxbx
xxxxxxxxxx
xxxxxbbxxx




 8
 7
 6                   30 31 32   
 5             28 27 29 33 
 4  9 10 11 12    26    34 35     
 3    17    13    25 40    36 
 2 18 16 15 14 23 24 39 38 37 
 1 19 20 21 22       41 42 43