a-be a-fu aaaa aaab aaae aaaf aaar aaba aabb aaea aafa aafb aaff aara aare aaru abaa abab abae abaf abar abau abb- abba abbb abbe abbr abee aber abff abra abua abue abuf aeaf aeer aer- aera afaa afar afee afer affa afr- afra afre afru afua afue arab arae araf arar arau arba arbe area aree aref areu arfa arfb arff arfu arr- arra arre arrr arru arua arub arue auaa aube auer aufe aur- aura aure baaa baaf baar baba babb babe babr babu baer baff bar- bara barb bare barf barr baru bau- bauf baur bbau bbbb bbeb beaf bear beau beba bebb bebe beeb beef beer befa befe beff bera bere berr beru beur brab brae braf brau brea breb bree bref brer brfu brrr brue buar buba bubb bube bubu buea buer bueu bufe buff bufr bur- bura burb bure burr buru eaaf eaba eafb eara earb eare ebba ebbr eber ebru ebur eeea eeee eefa eefe eera efab efbr effa efua eraf erau erba erbb erbe ereb erer erra erre erua erub erur euba euer eur- eura eure faaa faba fabe fabu faeb fafa fafe faff fara farb fare farr faru faue faur fbar feaf fear feba feeb feer fefe feff fera ferb fere ferr feru ffar ffee ffff ffrr frab frae frau frea free frub frue fuar fubb fubu fuff fufu fur- fura fure furr raab raaf raba rabb rabe rabu raef raer rafa rafe raff rara rarb rare rarf raua raub raue rauf rbaf rbbb rbbr rea- reae reaf rear reau reba rebb rebe rebu reeb reef refe reff refr refu rera rere reru reue reuf reuu rfae rfef rrrr ruba rubb rube rubu ruer rufa rufe ruff rura rure ruru uafa uaru uaua ubar ubba ubbe uber ubra ueba uefa ufer uffa uffe ufra urau urba urbe ure- urea urfa urfe urff urra urre urur uuuu