a-fu aaaa aaab aaad aaaf aaar aaba aabb aabd aada aadu aafa aafb aafd aaff aara aard aaru abaa abab abad abaf abar abau abb- abba abbb abbr abda abdu abff abra abua abud abuf adaa adab adad adar adba adda addd addr addu adfa adra adua adub adur afaa afad afar afdb affa afr- afra afru afua afud arab arad araf arar arau arba arda ardf ardu arfa arfb arff arfu arr- arra arrr arru arua arub arud auaa aur- aura aurd baaa baad baaf baar baba babb babr babu bada badb badd badr badu baff bar- bara barb bard barf barr baru bau- baud bauf baur bbad bbau bbbb bbdd bd-r bduf brab brad braf brau brda brfu brrr brud buad buar buba bubb bubu buda budb budd budu buff bufr bur- bura burb burd burr buru daab daad daar daau daba dabb dabu dada dadu dafa daff dara darb dard darf darr daru daub daud daur dbar dddd ddub dfaf dffa dfrf draa drab drad draf drar drau drba drda drra drua drub druu duaa duab duad duar dub- duba dubb dubu duda dudd dudu duff dufu dura duru duur faaa faad faba fabd fabu fada fadd fafa faff fara farb fard farr faru faud faur fbar ffar ffff ffrr frab frad frau frub fuad fuar fubb fubu fuda fudd fuff fufu fur- fura furr raab raad raaf raba rabb rabu rada radd radr radu rafa raff rara rarb rarf raua raub raud rauf rbaf rbbb rbbr rdfa rrad rrrr ruad ruba rubb rubu ruda rudd rufa ruff rura rurd ruru ruud uafa uaru uaua ubar ubba ubra ubud udaa udad udar udau udra uffa ufra urad urau urba urda urdu urfa urff urra urur uuuu