a-a a-b a-c aaa aab aac aak aao aar aau ab- aba abb abc abk abo abr abu ac- aca acb acc ack aco acr acu aka akb akc akk ako akr aku aoa aob aoc aok aoo aor aou ar- ara arb arc ark aro arr aru au- aua aub auc auk auo aur b-u baa bab bac bak bao bar bau bba bbb bbc bbk bbo bbr bbu bca bcb bcc bck bco bcr bcu bka bkb bkc bkk bko bkr boa bob boc bok boo bor bou bra brb brk bro brr bru bua bub buc buk buo bur buu c-- caa cab cac cak cao car cau cba cbb cbc cbk cbo cbr cbu cca ccb ccc cck cco ccr ccu cka ckb ckc cko co- coa cob coc cok coo cor cou cra crb crc crk cro crr cru cua cub cuc cuk cuo cur cuu ka- kaa kab kac kak kao kar kau kba kbb kbc kbk kbo kbr kbu kca kcb kcc kck kcr kcu kkb kkc kkk kkr kku koa kob koc kok koo kor kou kra krc krk kro krr kru kub kuc kuk kur kuu oaa oab oac oak oao oar oau ob- oba obb obc obk obo obr obu oc- oca ocb occ ock oco ocr ocu oka okb okc okk oko okr oku oo- ooa oob ooc ook ooo oor or- ora orb orc ork oro orr oru ou- oua ouc ouk ouo our ra- raa rab rac rak rao rar rau rba rbb rbc rbk rbo rbr rbu rca rcb rcc rco rcr rcu rkb rkc rkk rko rku roa rob roc rok roo ror rou rra rrb rrc rrk rrr rru rua rub ruc ruk ruo rur ruu ua- uaa uab uac uak uao uar uau uba ubb ubc ubk ubo ubr ubu uca ucb ucc uck uco ucr ucu uka ukb ukc ukk ukr uku uoa uob uoc uok uoo uor ur- ura urb urc urk uro urr uru uua uuc uur uuu

a-ak a-ok aaaa aaab aaac aaar aaba aabb aabc aaca aacb aacc aack aaco aacr aacu aaka aaku aaoo aara aarc aaro aaru abaa abab abac abak abar abau abb- abba abbb abbo abbr abca abcb abcc abcr aboa abob abok aboo abor abou abra abrc abro abua abuk acaa acab acac acar acba acca accc acco accu acoa acor acou acr- acra acrc acro acrr acu- acuo acur akaa akao akar akca akka akko akku akok akr- akra akua aoba aoca aora aorb arab arac arak arar arau arba arc- arca arco arka arko aroa arob aroo aror arr- arra arrc arrk arro arrr arru arua arub auaa auca aur- aura auro baaa baak baar baba babb babo babr babu bac- baca bacc back baco bak- baka bako bakr baku bar- bara barb barc bark baro barr baru bau- bauk baur bbau bbbb bbrc bcaa bcar bcbc bcca bccc bcor bcra bcru bcuc boab boac boak boar boba bobb bobo bobu boca bock boco bocu boka boko boku boob booc book boor bor- bora bork boro borr boru boua bouk bour brab brac brak brao brau brca brcb brka brkb broa brob broc brok broo bror brou brrr bruc buar buba bubb bubo bubu buca bucc buck buco bucu buka bukk buko buku bur- bura burb burk buro burr buru c-bo caaa caab caac caba cabo cabu cac- caca cacc cack caco cacr caka caor cara carb carc cark caro carr cauc cauk cauo cbac cbar cbbc cbca cbcc cbcr cbcu cbka cbko cbkr ccaa ccab ccac ccar ccba ccbc ccca cccb cccc cccu ccob ccoc ccra ccrc ccuc ckac ckbc ckck ckco ckoa ckob ckoc ckoo ckor ckrc coak coba cobb cobo cobu coca cock coco cocu cok- coka coko coob cook cor- cora corb corc cork coro corr coua coub couk cour crab crac crar crau crbc crbu crca crcc crcr crkc crob croc crok croo cror crub cruk cuau cub- cuba cubb cuca cucc cuck cuk- cuka cura curb curo curr kaaa kaab kaak kaar kaba kabb kabc kabo kabr kabu kacb kacc kaco kacu kaka kakc kakk kako kaku kaoa kaoc kaok kaor kara karb kark karo karr karu kau- kaub kauc kauk kauo kaur kbaa kbab kbac kbak kbar kbba kbbb kbbc kbbk kbbo kbbr kbbu kbca kbcb kbck kbco kbcr kbcu kbkb kbkk kbko kbkr kboa kbob kboc kbok kboo kbra kbrb kbrc kbrk kbro kbru kbua kbub kbuc kbuk kbur kbuu kcaa kcab kcac kcar kcau kcba kcbc kcbk kcbr kcbu kcca kccb kccc kcck kccr kccu kckc kckk kcko kckr kcob kcor kcou kcrc kcro kcrr kcru kcua kcub kcuk kkaa kkac kkar kkba kkbb kkbo kkbr kkcb kkck kkco kkcr kkkk kkoa kkob kkoo kkor kkrb kkrc kkrk kkro kkrr kkua kkuu koab koac koak koar koba kobb kobc kobk kobo kobr kobu koca kocb kock koka kokb kokc kokk koko kokr koku koob kooc kook kooo koor koou kora korb korc kork koro korr koru koua koub kour kouu krab krac krak krar krba krbb krbk krbr krca krcb krcc krco krcu krka krkc krkk krko krkr krku kroa krob kroc krok kroo kror krrb krrc krrk krro krrr krua kruc kruk krur kuac kuar kuau kuba kubb kubc kubo kubr kubu kuca kucb kucc kuco kucr kuka kukk kuku kuoa kuok kuoo kura kurb kurk kuro kurr kuru kuub kuuk kuur kuuu oaau oara obak obba obbo obkb obok obor obra obro ocab ocac ocak ocbc occa occc ocra ocro ocrr ocur okak okcu okka okko okok okor okra okro okur ooaa ooak ooba oocr ooku oooo oora orab orac orak orao orar orba orbb orbo orbu orca orco orka orko oro- orok oror orra orro orub ouac oucc our- oura ouro ouu- raab raak raba rabb rabk rabo rabu rac- raca racc rack raco racu raka rakk raku raob raoc raok rara rarb rark raro raua raub rauc rauk rbbb rbbr rcac rcbc rcbo rccb rccc roab roak roar