A A C B B A A B C C A B B C C B B B C B B A C A B B A C A B B A C C C B A A C B B A A B B C B C C A C B A C A B A B A A C B C A A B A C C A A B A A B C A A A B C C A A B B A C A C B B A C A B A B B A A C C B C A A C C B A C C B B C A B B A C B B C B B A C A C B B B A C B B B B C C A A C A B C B A A C C B B A C A B C A B B A C A C C C B C C ? B B A C A C A C C C A B ？
