a-a a-b a-c aaa aab aac aad aaf aak aao aar ab- aba abb abc abd abf abk abo abr ac- aca acb acc acd acf ack aco acr ad- ada adb adc add adf adk ado adr af- afa afb afc afd aff afk afo afr aka akb akc akd akk ako akr aoa aob aoc aod aof aok aoo aor ar- ara arb arc ard arf ark aro arr baa bab bac bad baf bak bao bar bba bbb bbc bbd bbf bbk bbo bbr bca bcb bcc bcd bcf bck bco bcr bda bdb bdc bdd bdf bdk bdo bdr bfa bfb bfc bfd bff bfo bfr bka bkb bkc bkf bkk bko bkr boa bob boc bod bof bok boo bor bra brb brd brf brk bro brr c-- caa cab cac cad caf cak cao car cba cbb cbc cbd cbf cbk cbo cbr cca ccb ccc ccd ccf cck cco ccr cda cdb cdc cdd cdf cdk cdo cdr cfa cfb cfc cfd cff cfk cfo cfr cka ckb ckc ckd cko co- coa cob coc cod cof cok coo cor cra crb crc crd crf crk cro crr daa dab dac dad daf dak dao dar dba dbb dbc dbd dbf dbk dbo dbr dca dcb dcc dcd dcf dck dco dcr dda ddb ddc ddd ddf ddk ddo ddr dfa dfb dfc dfd dff dfk dfo dfr dka dkb dkc dkk dko dkr doa dob doc dod dof dok doo dor dra drb drc drd drk dro drr faa fab fac fad faf fak fao far fba fbb fbc fbd fbf fbk fbo fbr fca fcb fcc fcd fcf fck fco fcr fda fdb fdc fdd fdf fdk fdo fdr ffa ffc ffd fff ffk ffo ffr fka fkb fkc fkf fkk foa fob foc fof fok foo for fra frb frc frd frf frk fro frr ka- kaa kab kac kad kaf kak kao kar kba kbb kbc kbd kbf kbk kbo kbr kca kcb kcc kcd kck kcr kda kdb kdc kdf kdk kdo kdr kfa kfc kfd kff kfo kkb kkc kkk kkr koa kob koc kod kof kok koo kor kra krc krd krf krk kro krr oaa oab oac oad oaf oak oao oar ob- oba obb obc obd obf obk obo obr oc- oca ocb occ ocd ocf ock oco ocr oda odb odc odd odf odo odr of- ofa ofb ofc ofd off ofo ofr oka okb okc okd okk oko okr oo- ooa oob ooc ood oof ook ooo oor or- ora orb orc ord orf ork oro orr ra- raa rab rac rad raf rak rao rar rba rbb rbc rbd rbf rbk rbo rbr rca rcb rcc rcd rcf rco rcr rda rdb rdc rdd rdf rdo rdr rfa rfb rfc rfd rff rfk rfo rfr rkb rkc rkf rkk rko roa rob roc rod rof rok roo ror rra rrb rrc rrd rrf rrk rrr

a-ak a-do a-ok aaaa aaab aaac aaad aaaf aaar aaba aabb aabc aabd aaca aacb aacc aacd aacf aack aaco aacr aada aadc aafa aafb aafc aafd aaff aaka aaoo aara aarc aard aaro abaa abab abac abad abaf abak abar abb- abba abbb abbo abbr abca abcb abcc abcd abcf abcr abda abdo abff aboa abob abod abof abok aboo abor abra abrc abro acaa acab acac acad acar acba acca accc accd accf acco acda acdb acdc acdf acfc acfd ackd acoa acod acor acr- acra acrc acro acrr adaa adab adac adad adak adao adar adba adbc adcc adda addc addd addo addr adfa adfc adob adoc adod adok adoo ador adra adro afaa afad afak afao afar afca afcb afcc afdb afdc affa affc affo afka afkr afoa afoo afor afr- afra afrc afro akaa akao akar akca akka akko akok akr- akra aoba aoca aora aorb arab arac arad araf arak arar arba arc- arca arco arda ardc ardf ardo arfa arfb arfc arff arka arko aroa arob arod aroo aror arr- arra arrc arrk arro arrr baaa baad baaf baak baar baba babb babo babr bac- baca bacc back baco bada badb badd bado badr bafc baff bafo bak- baka bako bakr bar- bara barb barc bard barf bark baro barr bbad bbbb bbdd bbdo bbfc bbrc bcaa bcar bcbc bcca bccc bcda bcfc bcof bcor bcra bd-r bdbc bddc bfca boab boac boad boak boar boba bobb bobo boca bock boco boda bodb bodo bofa bofd boff boka boko boob booc bood boof book boor bor- bora bord borf bork boro borr brab brac brad braf brak brao brca brcb brda brdo brfc brka brkb broa brob broc brod brok broo bror brrr c-bo c-cd caaa caab caac caaf caba cabf cabo cac- caca cacc cack caco cacr cada cadc cadd cado cadr cafa cafb cafc caff caka caod caor cara carb carc card carf cark caro carr cbac cbar cbbc cbca cbcc cbcr cbdb cbdc cbdo cbfb cbfc cbka cbko cbkr cbrd ccaa ccab ccac ccad ccaf ccar ccba ccbc ccca cccb cccc cccf ccdc ccdf ccdr ccfa ccfc ccfd ccff ccob ccoc ccod ccra ccrc ccrf cd-r cdaa cdac cdad cdba cdbf cdda cddb cddr cdfa cfaa cfab cfac cfao cfar cfbc cfbr cfca cfcb cfcf cfco cfda cffb cffr cfoa cfor cfra cfrb ckac ckbc ckck ckco ckdo ckfr ckoa ckob ckoc ckoo ckor ckrc ckrd coad coak coba cobb cobo coca cock coco coda codd cofc coff cok- coka coko coob cood coof cook cor- cora corb corc cord corf cork coro corr crab crac craf crar crbc crca crcc crcr crda crdc crfc crkc crob croc crod crok croo cror d-bo daab daad daar daba dabb dabo daca dada dado dafa dafc daff dafo daka dako dara darb darc dard darf dark daro darr dbar dbcc dbfc dbfo dcbc dcca dccb dccc dcdb dcfc dcra dcrk dddd ddoc ddrc dfaf dfcc dfco dffa dfrf dkba dkdc doab doak doar doba dobb doca dock doco