-ous bbbb bbbs bobb bobo bobs bobu boko boks boku boob book boor boos bor- bork boro borr bors boru bosk boso boss bosu bouk bour bous brkb brob brok broo bror bros brou brrr brrs brsb brsr brus bsos bubb bubo bubs bubu bukk buko buku bur- burb burk buro burr burs buru busk buss busu buus k-os kbbb kbbk kbbo kbbr kbbs kbbu kbkb kbkk kbko kbkr kbob kbok kboo kbos kbrb kbrk kbro kbru kbsb kbsk kbso kbsr kbss kbsu kbub kbuk kbur kbus kbuu kkbb kkbo kkbr kkbs kkkk kkob kkoo kkor kkrb kkrk kkro kkrr kkrs kksr kkss kksu kkus kkuu kobb kobk kobo kobr kobs kobu kokb kokk koko kokr koks koku koob kook kooo koor koos koou korb kork koro korr kors koru kos- kosb koso kosr koss kosu koub kour kous kouu krbb krbk krbr krkk krko krkr krks krku krob krok kroo kror kros krrb krrk krro krrr krrs krsk krsr krss krsu kruk krur ksbr ksbs kskb kskk ksko kskr ksks ksku ksob ksok ksoo ksor ksos ksou ksrb ksro ksrr ksrs ksso kssr ksss kssu ksub ksuu kubb kubo kubr kubs kubu kukk kuks kuku kuok kuoo kuos kurb kurk kuro kurr kurs kuru kusb kuso kusu kuub kuuk kuur kuuu obbo obkb obok obor obos obro obsr obss obus okko okok okor okro okso okur okus ooku oooo ooos oous orbb orbo orbs orbu orko oro- orok oror oros orro orrs orsk orso orsu orub orus osku osoo osor osos osro ossb osso ossu oubs our- ouro ours ouu- rbbb rbbr rbbs rbss rkos rkss rob- robb robo robs robu rokk roko rokr roks roku roob rook roor roos rork roro roru roso ross roub rouk rous rrrr rsos rubb rubs rubu rukk ruku ruok ruro rurs ruru rusk ruso russ rusu s-os sbbs sbor sbrk sbus skor skss skur sobo sobr sobs sobu sokk soko soku sook soor soos sorb soro sorr sors soru soso soss souk sour sous sros srub ssbr ssrs sssb ssss sub- subb subo subs suks suku suor suos sur- suro surr surs suru sus- susk suso suss susu suus ubbo ubos ukko ukok ukur uor- urbs uro- urok uroo urso urss ursu uruk urur urus us-k usbr usbs usos ussb ussr usss ussu usus uuuu