bbbb bbeb bbet bebb bebe beeb beem beer beet beme bemu bere berm berr bert beru bete bett betu beur breb bree brem brer bret brrm brrr brue brum brut btrt bttb bubb bube bubu buem buer bueu bum- bumb bur- burb bure burm burr burt buru but- bute butt ebbr eber ebru ebur eeee eete eetu embe embr emer emet emeu emme emmu emre emte erbb erbe ereb erem erer eret erme erre ertu erub erum erur etbr etee etem eter etre etrm ette ettu euer eur- eure eurt mebe meem meer meet meme memr memu mer- merb mere merm mert meru met- mete mett metu meum mmmm mrbb mrbm mreb mree mrtm mrtt mtre mtrr mttr mube muee muet mume mumm mumu mure murr murt muru mute mutt mutu muut rbbb rbbr rebb rebe rebu reeb reem reet reme rere rert reru rete retr rett reue reut reuu rmtu rrrr rrum rtee rubb rube rubu ruer ruet rumb rume rumm rumt rure ruru rute rutt rutu tbrb tebu teem teer teet teme temu ter- tere term terr teru tete tetr tett tetu teut tmbr tmtt tre- tree trem tret treu trmb trmu trte trtr trub true trut truu ttbb tter tttt tubb tube tubr tubu tuer tuet tumb tume tumu turb ture turm turr turt turu tute tutt tutu tuum ubbe uber ubet umb- umbe umer umet umut urbe ure- uret urre urte urum urur urut uter utmb uttu uuuu