a-ak aaaa aaab aaac aaar aaba aabb aabc aabt aaca aacb aacc aack aacr aact aaka aara aarc aart aata aatc aatk aatt abaa abab abac abak abar abat abb- abba abbb abbr abbt abca abcb abcc abcr abct abra abrc abta ac-t acaa acab acac acar acat acba acca accc acct acr- acra acrc acrr acta actc actt akaa akar akca akka akr- akra arab arac arak arar arat arba arc- arca arct arka arr- arra arrc arrk arrr arrt arta artc artr at-t ataa atab atac atak atar atat atca atcc atck atcr atka atkt atra atrc atrk atta attr baaa baak baar baat baba babb babr bac- baca bacc back bact bak- baka bakr bakt bar- bara barb barc bark barr bart bata batc batt bbbb bbrc bcaa bcar bcat bcbc bcca bccc bcra bctc brab brac brak brat brca brcb brka brkb brrr brtc btaa btcc btrc btrt bttb caaa caab caac caat caba cac- caca cacc cack cacr caka cara carb carc cark carr cart cat- cata catb catc catt cbac cbar cbat cbbc cbca cbcc cbcr cbct cbka cbkr cbrt cbta cbtc ccaa ccab ccac ccar ccat ccba ccbc ccca cccb cccc ccra ccrc ccrt cctb cctc cctt ckac ckat ckbc ckck ckrc cktb crab crac crar crat crbc crca crcc crcr crkc crrt crtc ctab ctba ctca ctrc ctta kaaa kaab kaak kaar kaat kaba kabb kabc kabr kacb kacc kact kaka kakc kakk kakt kara karb kark karr kart kat- kata katb katc katk katr katt kbaa kbab kbac kbak kbar kbat kbba kbbb kbbc kbbk kbbr kbbt kbca kbcb kbck kbcr kbct kbkb kbkk kbkr kbra kbrb kbrc kbrk kbrt kbta kbtb kbtc kbtk kbtr kbtt kcaa kcab kcac kcar kcat kcba kcbc kcbk kcbr kcca kccb kccc kcck kccr kcct kckc kckk kckr kcrc kcrr kcrt kcta kctb kctc kkaa kkac kkar kkat kkba kkbb kkbr kkbt kkcb kkck kkcr kkct kkkk kkrb kkrc kkrk kkrr kkrt kktc kktk krab krac krak krar krat krba krbb krbk krbr krbt krca krcb krcc krka krkc krkk krkr krrb krrc krrk krrr krrt krta krtc krtk krtr ktaa ktak ktar ktat ktba ktbb ktbc ktbr ktbt ktcc ktck ktcr ktkb ktkc ktkk ktkr ktkt ktrb ktrc ktrk ktrr ktrt kttc kttk kttr kttt raab raak raat raba rabb rabk rac- raca racc rack ract raka rakk rakt rara rarb rark rata ratk ratt rbbb rbbr rcac rcbc rccb rccc rctc rrat rrrr rtca rtcc taa- taar taat taba tabb tabc taca tacc tack tact taka takk takt tara tarb tarc tark tarr tart tata tatb tatr tatt tbar tbca tbcb tbcc tbrb tbta tcca tccc tctc tkac traa trab trac trak trat trca trcc trra trtc trtr ttab ttbb tttt