-er a-a a-b a-c aaa aab aac aae aaf aak aao aar ab- aba abb abc abe abf abk abo abr ac- aca acb acc ace acf ack aco acr aea aeb aec aee aef aek aeo aer af- afa afb afc afe aff afk afo afr aka akb akc ake akk ako akr aoa aob aoc aoe aof aok aoo aor ar- ara arb arc are arf ark aro arr baa bab bac bae baf bak bao bar bba bbb bbc bbe bbf bbk bbo bbr bca bcb bcc bce bcf bck bco bcr be- bea beb bec bee bef bek beo ber bfa bfb bfc bfe bff bfo bfr bka bkb bkc bke bkf bkk bko bkr boa bob boc boe bof bok boo bor bra brb bre brf brk bro brr c-- caa cab cac cae caf cak cao car cba cbb cbc cbe cbf cbk cbo cbr cca ccb ccc cce ccf cck cco ccr ce- cea ceb cec cee cef cek ceo cer cfa cfb cfc cfe cff cfk cfo cfr cka ckb ckc cko co- coa cob coc coe cof cok coo cor cra crb crc cre crf crk cro crr eaa eab eac eae eaf eak eao ear eba ebb ebc ebe ebf ebk ebo ebr ec- eca ecb ecc ece ecf eck eco ecr eea eeb eec eee eef eek eeo eer ef- efa efb efc efe eff efo efr eka ekb ekc eke ekf eko ekr eo- eoa eob eoc eoe eof eok eoo eor era erb erc ere erf erk ero err faa fab fac fae faf fak fao far fba fbb fbc fbe fbf fbk fbo fbr fca fcb fcc fce fcf fck fco fcr fea feb fec fee fef fek feo fer ffa ffc ffe fff ffk ffo ffr fka fkb fkc fkf fkk foa fob foc foe fof fok foo for fra frb frc fre frf frk fro frr ka- kaa kab kac kae kaf kak kao kar kba kbb kbc kbe kbf kbk kbo kbr kca kcb kcc kce kck kcr ke- kea keb kec kee kef kek keo ker kfa kfc kff kfo kkb kkc kke kkk kkr koa kob koc koe kof kok koo kor kra krc krf krk kro krr oaa oab oac oae oaf oak oao oar ob- oba obb obc obe obf obk obo obr oc- oca ocb occ ocf ock oco ocr oea oeb oec oee oef oeo oer of- ofa ofb ofc ofe off ofo ofr oka okb okc oke okk oko okr oo- ooa oob ooc oof ook ooo oor or- ora orb orc ore orf ork oro orr ra- raa rab rac rae raf rak rao rar rba rbb rbc rbe rbf rbk rbo rbr rca rcb rcc rce rcf rco rcr re- rea reb rec ree ref rek reo rer rfa rfb rfc rfe rff rfk rfo rfr rkb rkc rke rkf rkk rko roa rob roc roe rof rok roo ror rra rrb rrc rrf rrk rrr

a-ak a-be a-ok aaaa aaab aaac aaae aaaf aaar aaba aabb aabc aaca aacb aacc aace aacf aack aaco aacr aaea aaec aafa aafb aafc aaff aaka aake aaoe aaoo aara aarc aare aaro abaa abab abac abae abaf abak abar abb- abba abbb abbe abbo abbr abca abcb abcc abcf abcr abec abee aber abff aboa abob abof abok aboo abor abra abrc abro acaa acab acac acae acar acba acca accc acce accf acco ace- acea acec acek acer acfc acfe acke acoa acoe acor acr- acra acrc acre acro acrr aeac aeaf aecb aeer aeka aer- aera aerc aero afaa afak afao afar afca afcb afcc afee afek afer affa affc affo afka afkr afoa afoe afoo afor afr- afra afrc afre afro akaa akae akao akar akca akee aker akka akko akok akr- akra akre aoba aoca aoce aora aorb arab arac arae araf arak arar arba arbe arc- arca arce arco area arec aree aref arek areo arfa arfb arfc arff arka arke arko aroa arob aroe aroo aror arr- arra arrc arre arrk arro arrr baaa baaf baak baar baba babb babe babo babr bac- baca bacc bace back baco baek baer bafc baff bafo bak- baka bake bako bakr bar- bara barb barc bare barf bark baro barr bbbb bbeb bbfc bbrc bcaa bcar bcbc bcca bccc bcec bcer bcfc bcof bcor bcra beaf beak bear beba bebb bebe bebo beca beck beeb beef beek beer befa befe beff befo beka beke beko beo- beof beok beor bera berc bere berk bero berr bfca boab boac boak boar boba bobb bobe bobo boca boce bock boco boea boec boee boef boeo boer bofa bofe boff boka boke boko boob booc booe boof book boor bor- bora bore borf bork boro borr brab brac brae braf brak brao brca brcb brce brea breb brec bree bref brek breo brer brfc brka brkb broa brob broc broe brok broo bror brrr c-bo caaa caab caac caaf caba cabe cabf cabo cac- caca cacc cace cack caco cacr caec caer cafa cafb cafc cafe caff caka cake caor cara carb carc care carf cark caro carr cbac cbar cbbc cbca cbcc cbce cbcr cbea cbec cbee cbef cber cbfb cbfc cbka cbko cbkr cbre ccaa ccab ccac ccaf ccar ccba ccbc ccca cccb cccc cccf ccee ccfa ccfc ccff ccob ccoc ccra ccrc ccre ccrf ceac cear ceba cec- ceca cece ceco ceeb ceec cef- cefa cefc ceke ceor cer- cera cerc cere cerf cero cfaa cfab cfac cfae cfao cfar cfbc cfbr cfca cfcb cfcf cfco cffb cffr cfoa cfor cfra cfrb cfre ckac ckbc ckbe ckck ckco cker ckfr ckoa ckob ckoc ckoo ckor ckrc coak coba cobb cobe cobo coca coce cock coco cofc cofe coff cok- coka coke coko coob coof cook cor- cora corb corc core corf cork coro corr crab crac craf crar crbc crca crcc crce crcr cre- crea creb crec cree creo crfc crkc crob croc