a-a a-b a-c aaa aab aac aak aao aas ab- aba abb abc abk abo abs ac- aca acb acc ack aco acs aka akb akc akk ako aks aoa aob aoc aok aoo aos as- asa asb asc ask aso ass baa bab bac bak bao bas bba bbb bbc bbk bbo bbs bca bcb bcc bck bco bcs bka bkb bkc bkk bko bks boa bob boc bok boo bos bsa bsb bsc bsk bso bss c-- caa cab cac cak cao cas cba cbb cbc cbk cbo cbs cca ccb ccc cck cco ccs cka ckb ckc cko cks co- coa cob coc cok coo cos csa csb csc csk cso css ka- kaa kab kac kak kao kas kba kbb kbc kbk kbo kbs kca kcb kcc kck kcs kkb kkc kkk kks koa kob koc kok koo kos ksa ksb ksc ksk kso kss oaa oab oac oak oao oas ob- oba obb obc obk obo obs oc- oca ocb occ ock oco ocs oka okb okc okk oko oks oo- ooa oob ooc ook ooo oos os- osa osb osc osk oso oss saa sab sac sak sao sas sba sbb sbc sbk sbo sbs sca scb scc sck sco scs sk- ska skb skc skk sko sks soa sob soc sok soo sos ss- ssa ssb ssc ssk sso sss

a-ak a-ok aaaa aaab aaac aaas aaba aabb aabc aaca aacb aacc aack aaco aacs aaka aaoo aasa aasc aass abaa abab abac abak abas abb- abba abbb abbo abbs abca abcb abcc abcs aboa abob abok aboo abos abs- absa abss acaa acab acac acas acba acca accc acco accs acks acoa acos acsa acsc acss akaa akao akas akca akka akko akok akos aksa aoba aoca aocs aoks aoss asaa asab asac asak asao asas asba asbo asc- asca ascb ascc asco aska asko asks asob asoc asok asos assa assc assk asso asss baaa baak baas baba babb babo babs bac- baca bacc back baco bacs bak- baka bako baks baos basa basc bask baso bass bbas bbbb bbbs bcaa bcas bcbc bcbs bcca bccc bccs bcos bcsa bcsc bcss boab boac boak boas boba bobb bobo bobs boca bock boco bocs boka boko boks boob booc book boos bosa bosc bosk boso boss bsaa bsac bsas bscs bsos bssc c-bo caaa caab caac caas caba cabo cabs cac- caca cacc cack caco caka caos casa casb casc cask caso cass cbac cbbc cbbs cbca cbcc cbcs cbka cbko cbsa cbsc ccaa ccab ccac ccas ccba ccbc ccca cccb cccc cccs ccob ccoc ccsa ccss ckac ckbc ckck ckco ckcs ckoa ckob ckoc ckoo ckos cksa cksb ckso coak coas coba cobb cobo cobs coca cock coco cok- coka coko coob cook coos cosa cosc coso coss csaa csab csac csak csao csas cscb cscc csco cscs cska csks csob csos cssa k-os kaaa kaab kaak kaas kaba kabb kabc kabo kacb kacc kaco kacs kaka kakc kakk kako kaks kaoa kaoc kaok kaos kas- kasa kasb kasc kask kaso kass kbaa kbab kbac kbak kbas kbba kbbb kbbc kbbk kbbo kbbs kbca kbcb kbck kbco kbcs kbkb kbkk kbko kboa kbob kboc kbok kboo kbos kbsa kbsb kbsk kbso kbss kcaa kcab kcac kcas kcba kcbc kcbk kcbs kcca kccb kccc kcck kckc kckk kcko kcob kcos kcsa kcsb kcsc kcss kkaa kkac kkba kkbb kkbo kkbs kkcb kkck kkco kkcs kkkk kkoa kkob kkoo kksa kkss koab koac koak koas koba kobb kobc kobk kobo kobs koca kocb kock kocs koka kokb kokc kokk koko koks koob kooc kook kooo koos kos- kosa kosb kosc koso koss ksab ksac ksak ksas ksba ksbc ksbs ksca kscb ksck ksco kscs kska kskb kskk ksko ksks ksob ksoc ksok ksoo ksos kssa ksso ksss oaks oasc oass obak obas obba obbo obkb obok obos obss ocab ocac ocak ocas ocbc occa occc ocks ocos ocsa okak okas okka okko okok oksa okso ooaa ooak ooba oooo ooos oosa osak osas osba osca oscc osco osoo osos ossa ossb osso s-os sa-c saab saac saak saas saba sabb sabc sabo sabs saca sacc sack saco sacs saka sakb sakk sako saks saos sasa sasc sask saso sass sbaa sbac sbas sbbs sbca sbcc sbcs sbsa scaa scab scac scak scas scba sccc sccs sck- scob scok scoo scsa scsc scso skab skac skss soak soas soba sobo sobs soca sock soco socs soka sokk soko sook soos sosa soso soss ssaa ssab ssac ssao ssas ssca sscc sscs ssoc sssa sssb sssc ssss

-aaa- aaaas aaaoc aaasa aaass aabaa aabba aacbc aacos aacsa aacsb aacss aakko abaab ababa ababs abaca aback abaco abacs abaka abako abasa abask abass abbac abbas abbos abcas abccc abkoo aboab abobo abook aboso acaca acacb acack acass accas acock acook acoss akaba akabo akaoa akasa akbas akkas akobo akoka akoko aokas aoos asaak asaba asabc asack asaco asaka asako asasa asbak asbca asbos ascao asco- askas askos asksa asoak asock asocs asoka asosa assab assac assas assoa assoc assos b-cas babak babas babbs babka baboo babos babsk bacab bacao bacas bacca bacco back- backa backs bacos bakka bakoa bakos baksa bakso basab basak basca basco baska basko basks baso- bassa basso bbook bcock bo-bo boaco boaks bobac bobak bobko boboc bobok bobos bocac bocao bocas bocca bocka bocks bocoa bocsa bokaa bokko bokok boksa booba boobs boock booco booko books boosa bosak bosas bosco boscs boska bosko bosks bossa bossk bosso bsaba bscco c-a-c ca-ca caaba cabas cabob caboc cabok cabos cacak cacao cacas cacks caco- cacoa cacso caoba casas casca casco casks casos casso ccass ccccc co-bo co-co coaks cobas cobbs cocao cocas cocc- cocco cocka cocks cocoa cocos cokak cokk- cooba cooks coosa cos-b cosas cosca cosco csaba csobs k-a-o kaaba kaaks kaaos kabaa kabab kabak kabas kabba kabob kabsa kakao kakas kakka kakko kako- kakos kaooa kasab kasak kasba kaska kasoa kasos kassa ko-ko kobos kocab kocak kocks kocsk kokab kokak kokka kokko