bbbb bbfn bftt bnor bnrr bobb bobo bobu boff bofu bonn bono bont bonu boob boof boon boor boot bor- borf born boro borr bort boru botb botn boto bott bouf boun bour bout brfu brno brob bron broo bror brot brou brrr brun brut btob btor btrt bttb bubb bubo bubu buff bufo bufr bunb bunn buno bunt bunu buon bur- burb burn buro burr burt buru but- buto butt ffff ffrr fftf ffun fntb fnuf fobt fofo fono font foof foon foot for- forb forn foro forr fort foto fott foun four fout frob fron frot frou frub frun ftub fubb fubu fuff fufu funf funt fuor fur- furn furo furr furt futo futu nbbo nbuf nfff nfon nfto nnnn nnot nntn nobo nobu non- nonn nono nont nonu noo- noob noon nooo noor noot nor- norb norf norn noro norr nort not- noto nott noun nour nout nron ntnu ntof ntru ntto nttr nuff nunn nuno nunt nuon nurn nurr nurt nuru nutt nutu obbo obon obor obot obro off- offo offr offu ofno ofor onno onon onor ont- onto onur onut ooff oont oooo oort ootb orbb orbo orbu orff orfu orno oro- orof oron oror orot orro orto orub oto- otof oton otoo otor otro otto ottu otur ouff oun- our- ourn ouro ourt out- outb outo ouu- rbbb rbbr rnbr rnnt rnot rnut rob- robb robo robt robu roff rofo rono ront roob roof roon roor root roro rort roru rotn roto rotr rott roub rouf roun rout rrrr rrun rtbf rtfb rubb rubu ruff rufo ruft runf runn runo runt ruro ruru ruto rutt rutu ruun tbnf tbrb tfot tnut tobo tobt tobu toff tofo toft tofu tonb tonn tono tonu toof toon toor toot torf torn toro torr tort toru toto totr tott toun tour tout trfr trno tron troo trot trou trtr trub trun trut truu ttbb ttff ttfn tton tttt tubb tubo tubr tubu tuff tufo tuft tufu tunb tunn tuno tunu tuor turb turf turn turo turr turt turu tuto tutt tutu tuuo ubbo ubon ubtf unno unon unrf unro untb unto unut uofo uor- urff urft uro- uroo urun urur urut utfo utor utto uttu uuno uutf uuuu