10 15
XXAXAXXCBXAAABC
ABXXBXXABBCXXXA
CXXBXXXCAXBCXBC
BACXXXCXBXXACXX
BAABBAXCCCAXBCX
CBAXXXCXXXXAXXX
XXXXCBACABXBBXX
ABAXCAXBCAXXACA
ABXCXCAXXXCXABX
XXCXXCCCCCBXCXA