a-ak a-be a-ok aaaa aaab aaae aaar aaba aabb aaea aaka aake aaoe aaoo aara aare aaro abaa abab abae abak abar abb- abba abbb abbe abbo abbr abee aber aboa abob abok aboo abor abra abro aeer aeka aer- aera aero akaa akae akao akar akee aker akka akko akok akr- akra akre aoba aora aorb arab arae arak arar arba arbe area aree arek areo arka arke arko aroa arob aroe aroo aror arr- arra arre arrk arro arrr baaa baak baar baba babb babe babo babr baek baer bak- baka bake bako bakr bar- bara barb bare bark baro barr bbbb bbeb beak bear beba bebb bebe bebo beeb beek beer beka beke beko beo- beok beor bera bere berk bero berr boab boak boar boba bobb bobe bobo boea boee boeo boer boka boke boko boob booe book boor bor- bora bore bork boro borr brab brae brak brao brea breb bree brek breo brer brka brkb broa brob broe brok broo bror brrr eaba eara earb eare earo ebba ebbo ebbr eber eboe eboo ebor ebro eeea eeee eeka eeke eera eero eka- ekab ekeb ekek eker ekka ekoa eoka eora eore erba erbb erbe ereb erer erke erob eroe eroo erra erre erro kaaa kaab kaak kaar kaba kabb kabe kabo kabr kaeo kaer kaka kake kakk kako kaoa kaok kaor kara karb kare kark karo karr kbaa kbab kbae kbak kbar kbba kbbb kbbe kbbk kbbo kbbr kbeb kbee kbek kbeo kber kbkb kbkk kbko kbkr kboa kbob kboe kbok kboo kbra kbrb kbre kbrk kbro kea- keak kear keba kebb kebe kebr keek keer keka kekb keke keko keok ker- kera kerb kere kerk kero kerr kkaa kkar kkba kkbb kkbe kkbo kkbr kkea kkkk kkoa kkob kkoo kkor kkrb kkre kkrk kkro kkrr koab koae koak koar koba kobb kobe kobk kobo kobr koea koka kokb koke kokk koko kokr koob kook kooo koor kora korb kore kork koro korr krab krae krak krar krba krbb krbe krbk krbr krea kreb kree krek kreo krka krke krkk krko krkr kroa krob kroe krok kroo kror krrb krre krrk krro krrr o-eo oaer oake oara oare obak obba obbo obea ober obkb oboe obok obor obra obre obro oera oere okak oker okka okko okok okor okra okre okro ooaa ooak ooba oobe ooer oooo oora oore orab orae orak orao orar orba orbb orbe orbo ore- orea oreb orek oreo orer orka orke orko oro- oroe orok oror orra orro raab raak raba rabb rabe rabk rabo raer raka rake rakk raob raok rara rarb rare rark raro rbbb rbbr rea- reae reak reao rear reba rebb rebe rebk rebo reeb reek reka reke reko rera rere rero roab roak roar rob- roba robb robe robo roea roer roka roke rokk roko rokr roob rook roor rora rore rork roro rrrr