aaaa aaab aaac aaas aaba aabb aabc aabt aaca aacb aacc aaco aacs aact aaoo aasa aasc aass aast aata aatc aatt abaa abab abac abas abat abb- abba abbb abbo abbs abbt abca abcb abcc abcs abct aboa abob aboo abos abot abs- absa abss abta abts ac-t acaa acab acac acas acat acba acca accc acco accs acct acoa acos acot acsa acsc acss acst acta actc acto acts actt aoba aoca aocs aoss aotc asaa asab asac asao asas asat asba asbo asc- asca ascb ascc asco asct asob asoc asos asot assa assc asso asss asst asta astb astc asto asts at-t ataa atab atac atas atat atbs atca atcc atco atcs atob atoc atos atot atsb atsc atst atta atto atts baaa baas baat baba babb babo babs bac- baca bacc baco bacs bact baos basa basc baso bass bast bata batc bato bats batt bbas bbbb bbbs bcaa bcas bcat bcbc bcbs bcca bccc bccs bcos bcsa bcsc bcss bctc bcts boab boac boas boat boba bobb bobo bobs boca boco bocs boob booc boos boot bosa bosc boso boss bost bota botb boto bots bott bsaa bsac bsas bsat bscs bsos bssc bsts btaa btcc btcs btob btss bttb c-bo caaa caab caac caas caat caba cabo cabs cac- caca cacc caco caos casa casb casc caso cass cast cat- cata catb catc cato cats catt cbac cbat cbbc cbbs cbca cbcc cbcs cbct cbot cbsa cbsc cbta cbtc ccaa ccab ccac ccas ccat ccba ccbc ccca cccb cccc cccs ccob ccoc ccsa ccss ccst cctb cctc cctt coas coat coba cobb cobo cobs coca coco coct coob coos coot cosa cosc coso coss cost cota cotb cotc coto cots cott csaa csab csac csao csas csat cscb cscc csco cscs csob csos csot cssa csta cstc csto csts ctab ctba ctbs ctca ctos ctot ctsa ctsc ctss ctta ctts oasc oass oast oats obas obba obbo obos obot obss obst obts ocab ocac ocas ocat ocbc occa occc occt ocos ocsa oct- octa octo octs ooaa ooba oooo ooos oosa oost ootb oots osas osat osba osca oscc osco osoo osos ossa ossb osso osta ostc osts otac otas otbs oto- otoo otos otsa otso otta otto otts s-os sa-c saab saac saas saat saba sabb sabc sabo sabs saca sacc saco sacs sact saos sasa sasc saso sass sast sata satb satc sato sats satt sbaa sbac sbas sbbs sbca sbcc sbcs sbct sbot sbsa sbst sbtc scaa scab scac scas scat scba sccc sccs scct scob scoo scot scsa scsc scso scst sctc scto scts soas soat soba sobo sobs sobt soca soco socs soos soot sosa soso soss sost sota sotc soto sots ssaa ssab ssac ssao ssas ssat ssca sscc sscs ssoc ssot sssa sssb sssc ssss ssta sstb sstc ssts stab stac stas stat stbc stbs stca stcc stcs stoa stob stoo stos stot stss sttc taa- taas taat taba tabb tabc tabo tabs taca tacc taco tacs tact taoa taos tasa tasb tasc tass tast tata tatb tato tats tatt tbas tbbs tbca tbcb tbcc tbst tbta tcbs tcca tccc tcos tctc tcts toab toas toat toba tobo tobs tobt toca toco tooa toos toot tosa tosb tosc toso toss tost tota totc toto tots tott tsaa tsao tsat tsbc tsca tscc tsob tsos tssa tsst tstc tsts ttab ttbb ttss tttt