a-a a-b a-c aaa aab aac aak aao aar aas ab- aba abb abc abk abo abr abs ac- aca acb acc ack aco acr acs aka akb akc akk ako akr aks aoa aob aoc aok aoo aor aos ar- ara arb arc ark aro arr ars as- asa asb asc ask aso asr ass baa bab bac bak bao bar bas bba bbb bbc bbk bbo bbr bbs bca bcb bcc bck bco bcr bcs bka bkb bkc bkk bko bkr bks boa bob boc bok boo bor bos bra brb brk bro brr brs bsa bsb bsc bsk bso bsr bss c-- caa cab cac cak cao car cas cba cbb cbc cbk cbo cbr cbs cca ccb ccc cck cco ccr ccs cka ckb ckc cko cks co- coa cob coc cok coo cor cos cra crb crc crk cro crr crs csa csb csc csk cso csr css ka- kaa kab kac kak kao kar kas kba kbb kbc kbk kbo kbr kbs kca kcb kcc kck kcr kcs kkb kkc kkk kkr kks koa kob koc kok koo kor kos kra krc krk kro krr krs ksa ksb ksc ksk kso ksr kss oaa oab oac oak oao oar oas ob- oba obb obc obk obo obr obs oc- oca ocb occ ock oco ocr ocs oka okb okc okk oko okr oks oo- ooa oob ooc ook ooo oor oos or- ora orb orc ork oro orr ors os- osa osb osc osk oso osr oss ra- raa rab rac rak rao rar ras rba rbb rbc rbk rbo rbr rbs rca rcb rcc rco rcr rcs rkb rkc rkk rko rks roa rob roc rok roo ror ros rra rrb rrc rrk rrr rrs rsa rsb rsc rsk rso rsr rss saa sab sac sak sao sar sas sba sbb sbc sbk sbo sbr sbs sca scb scc sck sco scr scs sk- ska skb skc skk sko skr sks soa sob soc sok soo sor sos sr- sra srb src srk sro srr srs ss- ssa ssb ssc ssk sso ssr sss

a-ak a-ok aaaa aaab aaac aaar aaas aaba aabb aabc aaca aacb aacc aack aaco aacr aacs aaka aaoo aara aarc aaro aars aasa aasc aass abaa abab abac abak abar abas abb- abba abbb abbo abbr abbs abca abcb abcc abcr abcs aboa abob abok aboo abor abos abra abrc abro abrs abs- absa abss acaa acab acac acar acas acba acca accc acco accs acks acoa acor acos acr- acra acrc acro acrr acrs acsa acsc acss akaa akao akar akas akca akka akko akok akos akr- akra aksa aoba aoca aocs aoks aora aorb aors aoss arab arac arak arar aras arba arbs arc- arca arco arcs arka arko arks aroa arob aroo aror aros arr- arra arrc arrk arro arrr arrs ars- arsa arsc arsk arso asaa asab asac asak asao asar asas asba asbo asc- asca ascb ascc asco ascr aska asko askr asks asob asoc asok asor asos asra asrc asro asrs assa assc assk asso assr asss baaa baak baar baas baba babb babo babr babs bac- baca bacc back baco bacs bak- baka bako bakr baks baos bar- bara barb barc bark baro barr bars basa basc bask baso bass bbas bbbb bbbs bbrc bcaa bcar bcas bcbc bcbs bcca bccc bccs bcor bcos bcra bcrs bcsa bcsc bcss boab boac boak boar boas boba bobb bobo bobs boca bock boco bocs boka boko boks boob booc book boor boos bor- bora bork boro borr bors bosa bosc bosk boso boss brab brac brak brao bras brca brcb brka brkb broa brob broc brok broo bror bros brrr brrs brsb brsr bsaa bsac bsas bscs bsos bsra bssc c-bo caaa caab caac caas caba cabo cabs cac- caca cacc cack caco cacr caka caor caos cara carb carc cark caro carr cars casa casb casc cask caso casr cass cbac cbar cbbc cbbs cbca cbcc cbcr cbcs cbka cbko cbkr cbsa cbsc ccaa ccab ccac ccar ccas ccba ccbc ccca cccb cccc cccs ccob ccoc ccra ccrc ccrs ccsa ccss ckac ckbc ckck ckco ckcs ckoa ckob ckoc ckoo ckor ckos ckrc cksa cksb ckso coak coas coba cobb cobo cobs coca cock coco cok- coka coko coob cook coos cor- cora corb corc cork coro corr cors cosa cosc coso coss crab crac crar cras crbc crca crcc crcr crkc crob croc crok croo cror crsa crss csaa csab csac csak csao csar csas cscb cscc csco cscr cscs cska csks csob csor csos csra csrc csrs cssa cssr k-os kaaa kaab kaak kaar kaas kaba kabb kabc kabo kabr kacb kacc kaco kacs kaka kakc kakk kako kaks kaoa kaoc kaok kaor kaos kara karb kark karo karr kars kas- kasa kasb kasc kask kaso kasr kass kbaa kbab kbac kbak kbar kbas kbba kbbb kbbc kbbk kbbo kbbr kbbs kbca kbcb kbck kbco kbcr kbcs kbkb kbkk kbko kbkr kboa kbob kboc kbok kboo kbos kbra kbrb kbrc kbrk kbro kbsa kbsb kbsk kbso kbsr kbss kcaa kcab kcac kcar kcas kcba kcbc kcbk kcbr kcbs kcca kccb kccc kcck kccr kckc kckk kcko kckr kcob kcor kcos kcrc kcro kcrr kcrs kcsa kcsb kcsc kcsr kcss kkaa kkac kkar kkba kkbb kkbo kkbr kkbs kkcb kkck kkco kkcr kkcs kkkk kkoa kkob kkoo kkor kkrb kkrc kkrk kkro kkrr kkrs kksa kksr kkss koab koac koak koar koas koba kobb kobc kobk kobo kobr kobs koca kocb kock kocs koka kokb kokc kokk koko kokr koks koob kooc kook kooo koor koos kora korb korc kork koro korr kors kos- kosa kosb kosc koso kosr koss krab krac krak krar kras krba krbb krbk krbr krca krcb krcc krco krcs krka krkc krkk krko krkr krks kroa krob kroc krok kroo kror kros krrb krrc krrk krro krrr krrs krsa krsc krsk krsr krss ksab ksac ksak ksar ksas ksba ksbc ksbr ksbs ksca kscb ksck ksco