-ous bbbb bbbs bblb bbls bffl bffs bfsr blls blob bloo blou blss blub bluf blur blus bobb bobo bobs bobu boff bofs bofu boll bolo bols bolu boob boof bool boor boos bor- borf boro borr bors boru boso boss bosu bouf boul bour bous brfu brls brob brol broo bror bros brou brrr brrs brsb brsr brus bsff bsfs bsos bubb bubo bubs bubu buff bufo bufr bulb bull buls bulu buol bur- burb burl buro burr burs buru buss busu buus fbrs fbus ffff ffrr ffss flob floo flor flos flou flub fluf fluo flur flus fobs fofo foll folo folr fols foof fool foos for- forb forl foro forr fors fosb foso foss foul four fous frob frol fros frou frsb frso frub fsfo fssf fubb fubs fubu fuff fufu full fuls fulu fuor fur- furl furo furr furs fuso fuss fusu lblr lbos lbrs llbs llll lloo lob- lobb lobo lobs loff loll lolo lols loob loof lool loor loos loro lors loso loss loul lour lous louu lrrr ls-r lsbu lsof lsso lssr lubs luff lufu lull lulu lurs luso luss obbo obls oblu obol obor obos obro obsr obss obus off- offo offr offs offu ofor ofus olbo olfs ollo olof olor olos olur ooff oofs oolo oooo ooos oous orbb orbo orbs orbu orff orfs orfu orlo orlu oro- orof oror oros orro orrs orso orsu orub orus oslo osoo osor osos osro ossb osso ossu osul oubs ouff ouls oulu our- ouro ours ouu- rbbb rbbr rbbs rbsl rbss rffl rlls rob- robb robo robs robu roff rofl rofo rolf roll rolo roob roof rool roor roos roro roru roso ross roub rouf roul rous rrrr rsos rssl rubb rubs rubu ruff rufo rull rulo ruro rurs ruru ruso russ rusu s-os sbbs sbor sbus sfls sfor sfos sfro sfss sfsu slob sloo slos slrs slsu slub slur sobo sobr sobs sobu sofo solf soll solo solr sols soof sool soor soos sorb soro sorr sors soru soso soss souf soul sour sous sros srub ssbr ssfl ssrl ssrs sssb sssf ssss sub- subb subl subo subs suf- suff sufr sufs sufu sul- sulf sull sulo sulu suor suos sur- surf suro surr surs suru sus- suso suss susu suus ubbo ublo ubls ubos ufos ullo ullr ulo- ulos ulul ulus uofl uofo uor- urbs urff urls uro- urol uroo urso urss ursu urur urus usbl usbr usbs usfl usfs uslu usos ussb ussf ussr usss ussu usul usus uulu uuuu