a-ii aaaa aaab aaac aaai aaba aabb aabc aabi aaca aacb aacc aaci aaib aaic aaii abaa abab abac abai abb- abba abbb abbi abca abcb abcc abci abia abib abic acaa acab acac acai acba acca accc acci aci- acia acic aiai aiba aica aicc aiia aiib aiic ba-i baaa baba babb babi bac- baca bacc baci baia baib baic bbbb bbci bcaa bcbc bcca bccc bcci bcia biba bibb bibi bica bicc bici caaa caab caac caba cabi cac- caca cacc caci caia caib caic cbac cbbc cbca cbcc cbia ccaa ccab ccac ccai ccba ccbc ccca cccb cccc ccci ccic ccii ciaa ciba cibc cibi cica cicc cici ciia ciii iaaa iaac iaai iaba iaca iacc iaia ibac ibca ibia icaa icab icac icai icbc icca iccb iccc icci iiac iica iiii