a-ak aaaa aaab aaac aaaf aaal aaba aabb aabc aabl aaca aacb aacc aacf aack aacl aafa aafb aafc aaff aafl aaka aala aalc aall abaa abab abac abaf abag abak abal abb- abba abbb abca abcb abcc abcf abcl abff abgl abla acaa acab acac acag acba acbl acca accc accf acfc acfl acga acla aclc afaa afak afca afcb afcc affa affc afgf afka afla aflc aflg agac agag agal agba agca agcc agfa agga agla aglc akaa akal akca akka alaa alac alag alak alal alb- alba albc alca alcc alfa alg- alga alk- alka alkb all- alla alll baaa baaf baak baal baba babb bac- baca bacc back bafc baff baga bagg bak- baka bakl bala balc balf balk ball bbbb bbfc bbga bblb bcaa bcbc bcbg bcca bccc bccl bcfc bfca bffl bfgf bgca bgfc blaa blab blac blag blak blfc blkb caaa caab caac caaf caal caba cabf cabg cac- caca cacc cack cafa cafb cafc caff cafl caga cagg caka cala calc calf calk call cbac cbal cbbc cbca cbcc cbcl cbfb cbfc cbga cbgb cbka cbkg cbkl cblb cblc ccaa ccab ccac ccaf ccag ccba ccbc ccca cccb cccc cccf cccl ccfa ccfc ccff ccfl ccga ccgc ccla cclc cclg cfaa cfab cfac cfbc cfca cfcb cfcf cfcl cffb cgac cgal cgcc cgcg cgfc ckac ckbc ckck ckcl ckga ckgl cklf cklg clab claf clag clkg f--k faaa faac faba faca facc fack fafa fafc faff fafg fagg fala falc falk fall fbla fcab fcal fcba fcca fccf ffcc ffff fkab flab flac flag flak flcl gaal gaba gabb gabl gack gafa gafb gafc gaff gaga gagg gala galk gall gbag gbfc gc-c gcaa gcal gcbc gccc gccf gcfc gclc gfcf gffa ggcl ggfg gggg glaa glab glak glbc glcc glfc kaaa kaab kaaf kaag kaak kaal kaba kabb kabc kabf kabg kacb kacc kacl kafa kafc kaff kag- kaga kagb kagc kagg kagl kaka kakc kakk kala kalb kalc kalf kalk kall kbaa kbab kbac kbak kbal kbba kbbb kbbc kbbf kbbg kbbk kbbl kbca kbcb kbck kbcl kbfb kbfc kbff kbfk kbfl kbga kbgb kbgg kbgl kbkb kbkf kbkg kbkk kbkl kbla kblb kblf kblg kbll kcaa kcab kcac kcal kcba kcbc kcbf kcbk kcbl kcca kccb kccc kcck kccl kcfa kcfb kcfc kcfg kcfl kcgc kcgf kcgl kckc kckf kckk kckl kcla kclc kclf kclk kcll kfab kfac kfal kfbc kfbk kfcf kffa kffb kfff kffg kffk kfka kfkb kfla kflb kflc kflf kflg kfll kgab kgac kgaf kgak kgal kgba kgbb kgbc kgcb kgcc kgcl kgfa kgff kgfk kgfl kgga kggf kggg kggl kgkl kgla kglb kglk kkaa kkac kkag kkal kkba kkbb kkbg kkbl kkcb kkck kkcl kkfg kkgb kkgl kkkk kklb kklc kklf kkll klaa klab klac klaf klag klak klal klbb klbc klbf klbl klca klcb klcc klck klcl klfa klfc klff klfg klga klgb klgl klka klkc klkk klkl klla kllb kllc kllk laaa laac laag laak laal laba laca lacc lack lacl lafb lafc laff lag- laga lagg laka lala lall lbcc lcac lcbc lcca lccc lcfc lcfg lfca lfcc lgca lgfl lkab lkal llcc llgc lllc llll