-er a-a a-b a-c aaa aab aac aae aak aao aar ab- aba abb abc abe abk abo abr ac- aca acb acc ace ack aco acr aea aeb aec aee aek aeo aer aka akb akc ake akk ako akr aoa aob aoc aoe aok aoo aor ar- ara arb arc are ark aro arr baa bab bac bae bak bao bar bba bbb bbc bbe bbk bbo bbr bca bcb bcc bce bck bco bcr be- bea beb bec bee bek beo ber bka bkb bkc bke bkk bko bkr boa bob boc boe bok boo bor bra brb bre brk bro brr c-- caa cab cac cae cak cao car cba cbb cbc cbe cbk cbo cbr cca ccb ccc cce cck cco ccr ce- cea ceb cec cee cek ceo cer cka ckb ckc cko co- coa cob coc coe cok coo cor cra crb crc cre crk cro crr eaa eab eac eae eak eao ear eba ebb ebc ebe ebk ebo ebr ec- eca ecb ecc ece eck eco ecr eea eeb eec eee eek eeo eer eka ekb ekc eke eko ekr eo- eoa eob eoc eoe eok eoo eor era erb erc ere erk ero err ka- kaa kab kac kae kak kao kar kba kbb kbc kbe kbk kbo kbr kca kcb kcc kce kck kcr ke- kea keb kec kee kek keo ker kkb kkc kke kkk kkr koa kob koc koe kok koo kor kra krc krk kro krr oaa oab oac oae oak oao oar ob- oba obb obc obe obk obo obr oc- oca ocb occ ock oco ocr oea oeb oec oee oeo oer oka okb okc oke okk oko okr oo- ooa oob ooc ook ooo oor or- ora orb orc ore ork oro orr ra- raa rab rac rae rak rao rar rba rbb rbc rbe rbk rbo rbr rca rcb rcc rce rco rcr re- rea reb rec ree rek reo rer rkb rkc rke rkk rko roa rob roc roe rok roo ror rra rrb rrc rrk rrr

a-ak a-be a-ok aaaa aaab aaac aaae aaar aaba aabb aabc aaca aacb aacc aace aack aaco aacr aaea aaec aaka aake aaoe aaoo aara aarc aare aaro abaa abab abac abae abak abar abb- abba abbb abbe abbo abbr abca abcb abcc abcr abec abee aber aboa abob abok aboo abor abra abrc abro acaa acab acac acae acar acba acca accc acce acco ace- acea acec acek acer acke acoa acoe acor acr- acra acrc acre acro acrr aeac aecb aeer aeka aer- aera aerc aero akaa akae akao akar akca akee aker akka akko akok akr- akra akre aoba aoca aoce aora aorb arab arac arae arak arar arba arbe arc- arca arce arco area arec aree arek areo arka arke arko aroa arob aroe aroo aror arr- arra arrc arre arrk arro arrr baaa baak baar baba babb babe babo babr bac- baca bacc bace back baco baek baer bak- baka bake bako bakr bar- bara barb barc bare bark baro barr bbbb bbeb bbrc bcaa bcar bcbc bcca bccc bcec bcer bcor bcra beak bear beba bebb bebe bebo beca beck beeb beek beer beka beke beko beo- beok beor bera berc bere berk bero berr boab boac boak boar boba bobb bobe bobo boca boce bock boco boea boec boee boeo boer boka boke boko boob booc booe book boor bor- bora bore bork boro borr brab brac brae brak brao brca brcb brce brea breb brec bree brek breo brer brka brkb broa brob broc broe brok broo bror brrr c-bo caaa caab caac caba cabe cabo cac- caca cacc cace cack caco cacr caec caer caka cake caor cara carb carc care cark caro carr cbac cbar cbbc cbca cbcc cbce cbcr cbea cbec cbee cber cbka cbko cbkr cbre ccaa ccab ccac ccar ccba ccbc ccca cccb cccc ccee ccob ccoc ccra ccrc ccre ceac cear ceba cec- ceca cece ceco ceeb ceec ceke ceor cer- cera cerc cere cero ckac ckbc ckbe ckck ckco cker ckoa ckob ckoc ckoo ckor ckrc coak coba cobb cobe cobo coca coce cock coco cok- coka coke coko coob cook cor- cora corb corc core cork coro corr crab crac crar crbc crca crcc crce crcr cre- crea creb crec cree creo crkc crob croc croe crok croo cror eaba eaca eacc eaec eara earb eare earo ebac ebba ebbc ebbo ebbr ebcc eber eboe eboo ebor ebro ecaa ecac ecao ecar ecbc ecbe ecca eccb eccc ecce ecco ecka ecko eco- ecra ecrc ecrr eeca eeea eeee eeka eeke eeoc eera eerc eero eka- ekab ekco ekeb ekek eker ekka ekoa eoka eora eore erba erbb erbe erca ercc erce ereb erec erer erke erob eroc eroe eroo erra errc erre erro kaaa kaab kaak kaar kaba kabb kabc kabe kabo kabr kacb kacc kace kaco kaeo kaer kaka kakc kake kakk kako kaoa kaoc kaok kaor kara karb kare kark karo karr kbaa kbab kbac kbae kbak kbar kbba kbbb kbbc kbbe kbbk kbbo kbbr kbca kbcb kbce kbck kbco kbcr kbeb kbec kbee kbek kbeo kber kbkb kbkk kbko kbkr kboa kbob kboc kboe kbok kboo kbra kbrb kbrc kbre kbrk kbro kcaa kcab kcac kcar kcba kcbc kcbk kcbr kcca kccb kccc kcck kccr kcea kceb kcec kcee kceo kckc kckk kcko kckr kcob kcoe kcor kcrc kcro kcrr kea- keak kear keba kebb kebc kebe kebr keca keck keco kecr keek keer keka kekb kekc keke keko keok ker- kera kerb kerc kere kerk kero kerr kkaa kkac kkar kkba kkbb kkbe kkbo kkbr kkcb kkck kkco kkcr kkea kkkk kkoa kkob kkoo kkor kkrb kkrc kkre kkrk kkro kkrr koab koac koae koak koar koba kobb kobc kobe kobk kobo kobr koca kocb kock koea koka kokb kokc koke kokk koko kokr koob kooc kook kooo koor kora korb korc kore kork koro korr krab krac krae krak krar krba krbb krbe