a-ak aaaa aaab aaac aaad aaaf aaar aaba aabb aabc aabd aabt aaca aacb aacc aacd aacf aack aacr aact aada aadc aadt aafa aafb aafc aafd aaff aaka aara aarc aard aart aata aatc aatf aatk aatt abaa abab abac abad abaf abak abar abat abb- abba abbb abbr abbt abca abcb abcc abcd abcf abcr abct abda abff abra abrc abta ac-t acaa acab acac acad acar acat acba acca accc accd accf acct acda acdb acdc acdf acdt acfc acfd acft ackd acr- acra acrc acrr acta actc actf actt adaa adab adac adad adak adar adat adba adbc adcc adda addc addd addr adfa adfc adra adta afaa afad afak afar afat afca afcb afcc afdb afdc affa affc afft afka afkr afr- afra afrc afta aftc akaa akar akca akka akr- akra arab arac arad araf arak arar arat arba arc- arca arct arda ardc ardf arfa arfb arfc arff arft arka arr- arra arrc arrk arrr arrt arta artc artr at-t ataa atab atac atad atak atar atat atca atcc atcf atck atcr atdt atfb atfc atka atkt atra atrc atrk atta attr baaa baad baaf baak baar baat baba babb babr bac- baca bacc back bact bada badb badd badr bafc baff baft bak- baka bakr bakt bar- bara barb barc bard barf bark barr bart bata batc batf batt bbad bbbb bbdd bbfc bbrc bcaa bcar bcat bcbc bcca bccc bcda bcfc bcra bctc bd-r bdbc bddc bfca bfta bftt brab brac brad braf brak brat brca brcb brda brdt brfc brka brkb brrr brtc btaa btaf btcc btdt btfc btrc btrt bttb c-cd caaa caab caac caaf caat caba cabf cac- caca cacc cack cacr cada cadc cadd cadr cafa cafb cafc caff caka cara carb carc card carf cark carr cart cat- cata catb catc catd catf catt cbac cbar cbat cbbc cbca cbcc cbcr cbct cbdb cbdc cbfb cbfc cbka cbkr cbrd cbrt cbta cbtc cbtf ccaa ccab ccac ccad ccaf ccar ccat ccba ccbc ccca cccb cccc cccf ccdc ccdf ccdr ccfa ccfc ccfd ccff ccra ccrc ccrf ccrt cctb cctc cctt cd-r cdaa cdac cdad cdba cdbf cdda cddb cddr cdfa cfaa cfab cfac cfar cfbc cfbr cfbt cfca cfcb cfcf cfda cffb cffr cfra cfrb cfrt cfta cftc cftk cftr ckac ckat ckbc ckck ckfr ckrc ckrd cktb crab crac craf crar crat crbc crca crcc crcr crda crdc crfc crkc crrt crtc crtf ctab ctba ctca ctcf ctfc ctrc ctta daab daad daar daba dabb dabt daca dact dada dafa dafc daff daft daka dara darb darc dard darf dark darr dart data datr datt dbar dbcc dbfc dbtt dcbc dcca dccb dccc dcct dcdb dcfc dcra dcrk dctc dddd ddrc dfaf dfcc dfdt dffa dfrf dftr dkba dkdc draa drab drac drad draf drak drar drat drba drbc drca drda drfc drra dtaa dtac dtcc dtfc f--k faaa faac faad faba fabd faca facc fack fact fada fadd fafa fafc faff fakt fara farb farc fard fark farr fart fata fatc fatf fatt fbar fcab fcar fcat fcba fcca fccf fcda fcra fdca fdtc ffar ffcc ffff ffrr fftf fkab frab frac frad frak frat frbc frcc frfc frta ft-c ftcd ftfc kaaa kaab kaaf kaak kaar kaat kaba kabb kabc kabd kabf kabr kacb kacc kacd kact kad- kada kadd kadf kadr kadt kafa kafc kaff kafr kaka kakc kakk kakt kara karb kard karf kark karr kart kat- kata katb katc katd katf katk katr katt kbaa kbab kbac kbad kbak kbar kbat kbba kbbb kbbc kbbd kbbf kbbk kbbr kbbt kbca kbcb kbck kbcr kbct kbdb kbdf kbdr kbfb kbfc kbff kbfk kbfr kbft kbkb kbkf kbkk kbkr kbra kbrb kbrc kbrd kbrf kbrk kbrt kbta kbtb kbtc kbtf kbtk kbtr kbtt kcaa kcab kcac kcad kcar kcat kcba kcbc kcbd kcbf kcbk kcbr kcca kccb kccc kccd kcck kccr kcct kcda kcdc kcdd kcdr kcfa kcfb kcfc kcfd kcft kckc kckf kckk kckr kcrc kcrr kcrt kcta kctb kctc kdaa kdab kdac kdad kdaf kdak kdar kdat kdbb kdbr kdca kdcc kdcd kdcr kddb kddc kddd kddf kddk kddr kdfc kdfr kdft kdka kdkb kdkd kdkk kdkr kdkt kdrb kdrf kdta kdtd kdtr kfab kfac kfar kfat kfbc kfbk kfbt kfcd kfcf kfcr kfda kffa kffb kfff kffk kfka kfkb kfra kfrc kfrd kfrr kfta kftc kftk kftt kkaa kkac kkar kkat kkba kkbb kkbd kkbr kkbt kkcb kkcd kkck kkcr kkct kkda kkdc kkdd kkdt kkfr kkft kkkk kkrb kkrc kkrf kkrk kkrr kkrt kktc kktk krab krac krad krak krar krat krba krbb krbd krbk krbr krbt krca krcb krcc krcd krda krdc krdd krdr krfc krfd krff krft krka krkc krkd krkk krkr krrb krrc krrf krrk krrr krrt krta krtc krtk krtr ktaa ktak ktar ktat ktba ktbb ktbc ktbr ktbt ktcc ktck ktcr ktdb ktdc ktdd ktdf ktdk ktdr ktfb ktfc ktkb ktkc ktkk ktkr ktkt ktrb ktrc ktrf ktrk ktrr ktrt kttc kttf kttk kttr kttt raab raad raaf raak raat raba rabb rabk rac- raca racc rack ract rada radc radd radr radt rafa rafc raff raft raka rakk rakt rara rarb rarf rark rata ratf ratk ratt rbaf rbbb rbbr rcac rcaf rcbc rccb rccc rcdc rcfc rcrd rctc rdac rdfa rffc rftc rkkf rrad rrat rrfc rrrr rtbf rtca rtcc rtdt rtfb rtfc taa- taaf taar taat taba tabb tabc taca tacc tack tact tada tafa tafc taff taft taka takk takt tara tarb tarc tard tarf tark tarr tart tata tatb tatr tatt tbaf tbar tbca tbcb tbcc tbcd tbrb tbta tcad tcca tccc tcdd tcfc tctc tdac tddb tdff tdkr tdra tfca tfdc tftc tkac traa trab trac trad traf trak trat trca trcc trfc trfd trfr trra trtc trtr ttab ttbb ttfa ttfc ttff tttt