a-a a-b a-c aaa aab aac aad aak aar aas ab- aba abb abc abd abk abr abs ac- aca acb acc acd ack acr acs ad- ada adb adc add adk adr ads aka akb akc akd akk akr aks ar- ara arb arc ard ark arr ars as- asa asb asc asd ask asr ass baa bab bac bad bak bar bas bba bbb bbc bbd bbk bbr bbs bca bcb bcc bcd bck bcr bcs bda bdb bdc bdd bdk bdr bds bka bkb bkc bkk bkr bks bra brb brd brk brr brs bsa bsb bsc bsd bsk bsr bss c-- caa cab cac cad cak car cas cba cbb cbc cbd cbk cbr cbs cca ccb ccc ccd cck ccr ccs cda cdb cdc cdd cdk cdr cds cka ckb ckc ckd cks cra crb crc crd crk crr crs csa csb csc csd csk csr css daa dab dac dad dak dar das dba dbb dbc dbd dbk dbr dbs dca dcb dcc dcd dck dcr dcs dda ddb ddc ddd ddk ddr dds dka dkb dkc dkk dkr dks dra drb drc drd drk drr drs dsa dsb dsc dsd dsk dsr dss ka- kaa kab kac kad kak kar kas kba kbb kbc kbd kbk kbr kbs kca kcb kcc kcd kck kcr kcs kda kdb kdc kdk kdr kds kkb kkc kkk kkr kks kra krc krd krk krr krs ksa ksb ksc ksd ksk ksr kss ra- raa rab rac rad rak rar ras rba rbb rbc rbd rbk rbr rbs rca rcb rcc rcd rcr rcs rda rdb rdc rdd rdr rds rkb rkc rkk rks rra rrb rrc rrd rrk rrr rrs rsa rsb rsc rsd rsk rsr rss saa sab sac sad sak sar sas sba sbb sbc sbd sbk sbr sbs sca scb scc scd sck scr scs sda sdb sdc sdd sdk sdr sds sk- ska skb skc skd skk skr sks sr- sra srb src srd srk srr srs ss- ssa ssb ssc ssd ssk ssr sss

a-ak aaaa aaab aaac aaad aaar aaas aaba aabb aabc aabd aaca aacb aacc aacd aack aacr aacs aada aadc aads aaka aara aarc aard aars aasa aasc aasd aass abaa abab abac abad abak abar abas abb- abba abbb abbr abbs abca abcb abcc abcd abcr abcs abda abra abrc abrs abs- absa absd abss acaa acab acac acad acar acas acba acca accc accd accs acda acdb acdc acds ackd acks acr- acra acrc acrr acrs acsa acsc acsd acss adaa adab adac adad adak adar adas adba adbc adcc adcs adda addc addd addr adds adra adrs adsa adsr adss akaa akar akas akca akka akr- akra aksa arab arac arad arak arar aras arba arbs arc- arca arcs arda ardc ards arka arks arr- arra arrc arrk arrr arrs ars- arsa arsc arsd arsk asaa asab asac asad asak asar asas asba asc- asca ascb ascc ascr asda asds aska askr asks asra asrc asrs assa assc assd assk assr asss baaa baad baak baar baas baba babb babr babs bac- baca bacc back bacs bada badb badd badr bads bak- baka bakr baks bar- bara barb barc bard bark barr bars basa basc bask bass bbad bbas bbbb bbbs bbdd bbrc bcaa bcar bcas bcbc bcbs bcca bccc bccs bcda bcds bcra bcrs bcsa bcsc bcss bd-r bdbc bddc bdsd brab brac brad brak bras brca brcb brda brds brka brkb brrr brrs brsb brsr bsaa bsac bsas bsbd bscs bsra bsrd bssc bssd c-cd caaa caab caac caas caba cabs cac- caca cacc cack cacr cada cadc cadd cadr cads caka cara carb carc card cark carr cars casa casb casc casd cask casr cass cbac cbar cbbc cbbs cbca cbcc cbcr cbcs cbdb cbdc cbds cbka cbkr cbrd cbsa cbsc ccaa ccab ccac ccad ccar ccas ccba ccbc ccca cccb cccc cccs ccdc ccdr ccds ccra ccrc ccrs ccsa ccsd ccss cd-r cdaa cdac cdad cdba cdcs cdda cddb cddr cdrs cdss ckac ckbc ckck ckcs ckrc ckrd cksa cksb crab crac crar cras crbc crca crcc crcr crda crdc crkc crsa crss csaa csab csac csak csar csas cscb cscc cscd cscr cscs csda csdb csdr cska csks csra csrc csrd csrs cssa cssd cssr daab daad daar daas daba dabb dabs daca dacs dada dads daka daks dara darb darc dard dark darr dars dasa dasb dasc dasd dask dass dbar dbas dbcc dbcs dbrs dbsa dbss dcas dcbc dcca dccb dccc dccs dcdb dcds dcra dcrk dcsc dcss dddd ddrc ddss dkba dkdc draa drab drac drad drak drar dras drba drbc drca drda drra drrs drsa dsac dsba dsbc dscc dscr dscs dsda dsdr dsrc dsrr dssa dssc kaaa kaab kaak kaar kaas kaba kabb kabc kabd kabr kacb kacc kacd kacs kad- kada kadd kadr kads kaka kakc kakk kaks kara karb kard kark karr kars kas- kasa kasb kasc kask kasr kass kbaa kbab kbac kbad kbak kbar kbas kbba kbbb kbbc kbbd kbbk kbbr kbbs kbca kbcb kbck kbcr kbcs kbdb kbdr kbds kbkb kbkk kbkr kbra kbrb kbrc kbrd kbrk kbsa kbsb kbsk kbsr kbss kcaa kcab kcac kcad kcar kcas kcba kcbc kcbd kcbk kcbr kcbs kcca kccb kccc kccd kcck kccr kcda kcdc kcdd kcdr kcds kckc kckk kckr kcrc kcrr kcrs kcsa kcsb kcsc kcsd kcsr kcss kdaa kdab kdac kdad kdak kdar kdbb kdbr kdbs kdca kdcc kdcd kdcr kddb kddc kddd kddk kddr kdka kdkb kdkd kdkk kdkr kdrb kdrs kdsc kdsd kdsk kdsr kdss kkaa kkac kkar kkba kkbb kkbd kkbr kkbs kkcb kkcd kkck kkcr kkcs kkda kkdc kkdd kkkk kkrb kkrc kkrk kkrr kkrs kksa kksd kksr kkss krab krac krad krak krar kras krba krbb krbd krbk krbr krca krcb krcc krcd krcs krda krdc krdd krdr krds krka krkc krkd krkk krkr krks krrb krrc krrk krrr krrs krsa krsc krsd krsk krsr krss ksab ksac ksak ksar ksas ksba ksbc ksbr