a-be a-fu aaaa aaab aaae aaaf aaar aaba aabb aaea aafa aafb aaff aara aare aaru abaa abab abae abaf abar abau abax 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 afxe arab arae araf arar arau arax arba arbe area aree aref areu arex arfa arfb arff arfu arr- arra arre arrr arru arua arub arue auaa aube auer aufe aur- aura aure auxa axaf axar axer axfr ba-x baaa baaf baar baba babb babe babr babu baer baff bar- bara barb bare barf barr baru barx bau- bauf baur baux bbau bbbb bbeb beaf bear beau beba bebb bebe beeb beef beer befa befe beff bera bere berr beru beur beux brab brae braf brau brax brea breb bree bref brer brex brfu brrr brue brux buar buba bubb bube bubu buea buer bueu bufe buff bufr bur- bura burb bure burr buru buxa eaaf eaba eafb eara earb eare eaux ebba ebbr eber ebru ebur eeea eeee eefa eefe eera efab efax efbr effa efua er-x eraf erau erba erbb erbe ereb erer erfx erra erre erua erub erur euba euer eur- eura eure exa- exer exrx faaa faba fabe fabu faeb faex fafa fafe faff fara farb fare farr faru faue faur faux faxe fbar feaf fear feba feeb feer fefe feff fera ferb fere ferr feru feux ffar ffee ffff ffrr frab frae frau frax frea free frex 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 raxa rbaf rbbb rbbr rea- reae reaf rear reau reba rebb rebe rebu reeb reef refe reff refr refu rera rere reru reue reuf reuu reux rexx 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 urex urfa urfe urff urra urre urur uuuu uxue xaar xara xare xbar xbee xbra xeer xefe xer- xera xexe xfer xura xuxa xuxu xxxx