??????????????????????????????????????????????????ABBBBAAAABBBBAABBBBBAABABABAABAAAAAAAAABABAAAAAABB
ABABAAAAABABBBBAAAABBBBAABBBBBAABABABAABAAAAAAAAAB
??????????????????????????????????????????????????????????????????????????????????????????ABAAAAAABB
??????????ABBBBAAAABBBBAABBBBBAABABABAABAAAAAAAAAB
????????????????????????????????????????????????????????????????????????????????????????????AAAAAABB
????????????????????????????????????????????????AB
-1