a-ak aaaa aaab aaac aaas aaba aabb aabc aabt aaca aacb aacc aack aacs aact aaka aasa aasc aass aast aata aatc aatk aatt abaa abab abac abak abas abat abb- abba abbb abbs abbt abca abcb abcc abcs abct abs- absa abss abta abts ac-t acaa acab acac acas acat acba acca accc accs acct acks acsa acsc acss acst acta actc acts actt akaa akas akca akka aksa akst asaa asab asac asak asas asat asba asc- asca ascb ascc asct aska asks askt assa assc assk asss asst asta astb astc asts at-t ataa atab atac atak atas atat atbs atca atcc atck atcs atka atkt atsb atsc atst atta atts baaa baak baas baat baba babb babs bac- baca bacc back bacs bact bak- baka baks bakt basa basc bask bass bast bata batc bats batt bbas bbbb bbbs bcaa bcas bcat bcbc bcbs bcca bccc bccs bcsa bcsc bcss bctc bcts bsaa bsac bsas bsat bscs bskt bssc bsts btaa btcc btcs btss bttb caaa caab caac caas caat caba cabs cac- caca cacc cack caka casa casb casc cask cass cast cat- cata catb catc cats catt cbac cbat cbbc cbbs cbca cbcc cbcs cbct cbka cbsa cbsc cbta cbtc ccaa ccab ccac ccas ccat ccba ccbc ccca cccb cccc cccs ccsa ccss ccst cctb cctc cctt ckac ckat ckbc ckck ckcs cksa cksb ckst cktb ckts csaa csab csac csak csas csat cscb cscc cscs cska csks cssa csta cstc csts ctab ctba ctbs ctca ctsa ctsc ctss ctta ctts kaaa kaab kaak kaas kaat kaba kabb kabc kacb kacc kacs kact kaka kakc kakk kaks kakt kas- kasa kasb kasc kask kass kast kat- kata katb katc katk kats katt kbaa kbab kbac kbak kbas kbat kbba kbbb kbbc kbbk kbbs kbbt kbca kbcb kbck kbcs kbct kbkb kbkk kbsa kbsb kbsk kbss kbst kbta kbtb kbtc kbtk kbts kbtt kcaa kcab kcac kcas kcat kcba kcbc kcbk kcbs kcca kccb kccc kcck kcct kckc kckk kcsa kcsb kcsc kcss kcst kcta kctb kctc kkaa kkac kkat kkba kkbb kkbs kkbt kkcb kkck kkcs kkct kkkk kksa kkss kkst kktc kktk kkts ksab ksac ksak ksas ksat ksba ksbc ksbs ksca kscb ksck kscs kska kskb kskk ksks kssa ksss ksst ksta kstb kstc kstk ksts kstt ktaa ktak ktas ktat ktba ktbb ktbc ktbt ktcc ktck ktcs ktkb ktkc ktkk ktks ktkt ktsa ktsc ktst kttc kttk ktts kttt sa-c saab saac saak saas saat saba sabb sabc sabs saca sacc sack sacs sact saka sakb sakk saks sasa sasc sask sass sast sata satb satc sats satt sbaa sbac sbas sbbs sbca sbcc sbcs sbct sbsa sbst sbtc sbtk scaa scab scac scak scas scat scba sccc sccs scct sck- scsa scsc scst sctc scts skab skac skat skss ssaa ssab ssac ssas ssat ssca sscc sscs sssa sssb sssc ssss ssta sstb sstc ssts stab stac stak stas stat stbc stbs stca stcc stcs stks stss sttc taa- taas taat taba tabb tabc tabs taca tacc tack tacs tact taka takk taks takt tasa tasb tasc task tass tast tata tatb tats tatt tbas tbbs tbca tbcb tbcc tbst tbta tcbs tcca tccc tctc tcts tkac tkts tsaa tsat tsbc tsca tscc tsks tssa tsst tstc tsts ttab ttbb ttss tttt