a-ii aaaa aaab aaac aaad aaai aaba aabb aabc aabd aabi aaca aacb aacc aacd aaci aada aadc aadi aaib aaic aaii abaa abab abac abad abai abb- abba abbb abbi abca abcb abcc abcd abci abda abdi abia abib abic abid acaa acab acac acad acai acba acca accc accd acci acda acdb acdc acdi aci- acia acic acid adaa adab adac adad adai adba adbc adbi adcc adci adda addc addd addi adia adib adic aiai aiba aica aicc aicd aida aidb aidc aidi aiia aiib aiic aiid ba-i baaa baad baba babb babi bac- baca bacc baci bada badb badd badi baia baib baic baid bbad bbbb bbci bbdd bcaa bcbc bcca bccc bcci bcda bcia bdbc bddc bdii biad biba bibb bibi bica bicc bici bida bidi c-cd caaa caab caac caba cabi cac- caca cacc caci cada cadc cadd cadi caia caib caic caid cbac cbbc cbca cbcc cbdb cbdc cbdi cbia cbid ccaa ccab ccac ccad ccai ccba ccbc ccca cccb cccc ccci ccdc ccdi ccic ccid ccii cdaa cdac cdad cdai cdba cdda cddb cdic cdii ciaa ciba cibc cibi cica cicc cici cida cidc cidi ciia ciid ciii daab daad daba dabb daca daci dada dadi daia daid dbcc dcbc dcca dccb dccc dcci dcdb dcia dcii dddd dia- diab diac diad diba dibb dica dici dida didi diii iaaa iaac iaai iaba iaca iacc iadb iadc iaia ibac ibad ibca ibia ibid icaa icab icac icad icai icbc icbd icca iccb iccc icci icdc icdd idad idca idda idia idic idid iiac iica iicd iida iiii