Sorry, that was my misunderstanding. After that I asked jin8 and he replied that he did not achieve it. I heard that someone has already cleared when...
Hmm... Here is another solution with 11 pieces, but I can't find a solution within 9 pieces. a a bb aa 99997 88677 88667 55461 54431 54331 22231...
I found a solution with 11 minos. 9 9 9aaa7 98877 688a7 66554 36544 33541 32221 *2b 1 **b 1 x*bbx
用逗号分隔用户名
