a-ak a-be a-ok aaaa aaab aaac aaae aaaf aaba aabb aabc aaca aacb aacc aace aacf aack aaco aaea aaec aafa aafb aafc aaff aaka aake aaoe aaoo abaa abab abac abae abaf abak abb- abba abbb abbe abbo abca abcb abcc abcf abec abee abff aboa abob abof abok aboo acaa acab acac acae acba acca accc acce accf acco ace- acea acec acek acfc acfe acke acoa acoe aeac aeaf aecb aeka afaa afak afao afca afcb afcc afee afek affa affc affo afka afoa afoe afoo akaa akae akao akca akee akka akko akok aoba aoca aoce baaa baaf baak baba babb babe babo bac- baca bacc bace back baco baek bafc baff bafo bak- baka bake bako bbbb bbeb bbfc bcaa bcbc bcca bccc bcec bcfc bcof beaf beak beba bebb bebe bebo beca beck beeb beef beek befa befe beff befo beka beke beko beo- beof beok bfca boab boac boak boba bobb bobe bobo boca boce bock boco boea boec boee boef boeo bofa bofe boff boka boke boko boob booc booe boof book c-bo caaa caab caac caaf caba cabe cabf cabo cac- caca cacc cace cack caco caec cafa cafb cafc cafe caff caka cake cbac cbbc cbca cbcc cbce cbea cbec cbee cbef cbfb cbfc cbka cbko ccaa ccab ccac ccaf ccba ccbc ccca cccb cccc cccf ccee ccfa ccfc ccff ccob ccoc ceac ceba cec- ceca cece ceco ceeb ceec cef- cefa cefc ceke cfaa cfab cfac cfae cfao cfbc cfca cfcb cfcf cfco cffb cfoa ckac ckbc ckbe ckck ckco ckoa ckob ckoc ckoo coak coba cobb cobe cobo coca coce cock coco cofc cofe coff cok- coka coke coko coob coof cook eaaf eaba eaca eacc eaec eafb ebac ebba ebbc ebbo ebcc ebfc eboe eboo ecaa ecac ecao ecbc ecbe ecca eccb eccc ecce ecco ecef ecfa ecfc ecka ecko eco- eeca eeea eeee eefa eefe eeka eeke eeoc efab efca efco efeo effa efke eka- ekab ekco ekeb ekek ekfc ekka ekoa eoka f--k faaa faac faba fabe fabo faca facc face fack faeb fafa fafc fafe faff fafo fake fako fcab fcba fcca fccf feaf feak feba febo fece feck feeb feek fefc fefe feff fefo feke feko feof ffcc ffee ffff fkab foaf foak foba foca foce fock foco fofo foke foof fook kaaa kaab kaaf kaak kaba kabb kabc kabe kabf kabo kacb kacc kace kaco kaeo kafa kafc kafe kaff kaka kakc kake kakk kako kaoa kaoc kaok kbaa kbab kbac kbae kbak kbba kbbb kbbc kbbe kbbf kbbk kbbo kbca kbcb kbce kbck kbco kbeb kbec kbee kbef kbek kbeo kbfb kbfc kbff kbfk kbfo kbkb kbkf kbkk kbko kboa kbob kboc kboe kbok kboo kcaa kcab kcac kcba kcbc kcbf kcbk kcca kccb kccc kcck kcea kceb kcec kcee kceo kcfa kcfb kcfc kcfo kckc kckf kckk kcko kcob kcoe kcof kea- keak keba kebb kebc kebe keca keck keco keef keek kefa kefb kefc keff keka kekb kekc keke keko keok kfab kfac kfbc kfbk kfcf kfco kfeb kffa kffb kfff kffk kfka kfkb kfok kfoo kkaa kkac kkba kkbb kkbe kkbo kkcb kkck kkco kkea kkkk kkoa kkob kkoo koab koac koae koak koba kobb kobc kobe kobk kobo koca kocb kocf kock koea kofa kofc kofe koff kofk kofo koka kokb kokc koke kokf kokk koko koob kooc kook kooo o-eo oafc oafo oake obak obba obbo obea obec obkb oboe obok ocab ocac ocak ocbc occa occc oce ocee ocef ocfa ocke oec- oeca oecc oeec ofek off- offa offc offe offo okak okka okko okok ooaa ooak ooba oobe ooff oooo