b-u bbb bbk bbo bbr bbs bbt bbu bkb bkk bko bkr bks bkt bob bok boo bor bos bot bou brb brk bro brr brs brt bru bsb bsk bso bsr bss bst bsu btb btk bto btr bts btt btu bub buk buo bur bus but buu k-t kbb kbk kbo kbr kbs kbu kkb kkk kkr kks kkt kku kob kok koo kor kos kot kou krk kro krr krs krt kru ksb ksk kso ksr kss kst ksu ktb ktk kto ktr kts ktt ktu kub kuk kur kus kut kuu ob- obb obk obo obr obs obt obu okb okk oko okr oks oku oo- oob ook ooo oor oos oot or- orb ork oro orr ors ort oru os- osb osk oso osr oss ost osu ot- otb otk oto otr ots ott otu ou- ouk ouo our ous out rbb rbk rbo rbr rbs rbt rbu rkb rkk rko rks rkt rku rob rok roo ror ros rot rou rrb rrk rrr rrs rrt rru rsb rsk rso rsr rss rst rsu rtb rtk rto rtr rts rtt rtu rub ruk ruo rur rus rut ruu sbb sbk sbo sbr sbs sbt sbu sk- skb skk sko skr sks skt sku sob sok soo sor sos sot sou sr- srb srk sro srr srs srt ss- ssb ssk sso ssr sss sst ssu stb stk sto str sts stt stu sub suk suo sur sus sut suu tbb tbk tbo tbr tbs tbt tbu tkb tkk tko tkr tks tkt to- tob tok too tor tos tot tou trb trk tro trr trs trt tru tsb tsk tso tsr tss tst tsu ttb ttk tto ttr tts ttt ttu tub tuk tuo tur tus tut tuu ubb ubk ubo ubr ubs ubt ubu ukb ukk ukr uku uob uok uoo uor uos uot ur- urb urk uro urr urs urt uru usb usk uso usr uss ust usu utb utk uto utr uts utt utu uur uus uut uuu

-ous bbbb bbbs bobb bobo bobs bobu boko boks boku boob book boor boos boot bor- bork boro borr bors bort boru bosk boso boss bost bosu botb boto bots bott bouk bour bous bout brkb brob brok broo bror bros brot brou brrr brrs brsb brsr brst brus brut bskt bsos bsts btob btor btrt btss bttb btus bubb bubo bubs bubu bukk buko buku bur- burb burk buro burr burs burt buru busk buss bust busu but- buto buts butt buus k-os kbbb kbbk kbbo kbbr kbbs kbbt kbbu kbkb kbkk kbko kbkr kbob kbok kboo kbos kbot kbrb kbrk kbro kbrt kbru kbsb kbsk kbso kbsr kbss kbst kbsu kbtb kbtk kbto kbtr kbts kbtt kbub kbuk kbur kbus kbut kbuu kkbb kkbo kkbr kkbs kkbt kkkk kkob kkoo kkor kkot kkrb kkrk kkro kkrr kkrs kkrt kksr kkss kkst kksu kktk kkts kktu kkus kkut kkuu kobb kobk kobo kobr kobs kobu kokb kokk koko kokr koks koku koob kook kooo koor koos koot koou korb kork koro korr kors kort koru kos- kosb koso kosr koss kost kosu kotb kotk koto kotr kots kott kotu koub kour kous kout kouu krbb krbk krbr krbt krkk krko krkr krks krku krob krok kroo kror kros krrb krrk krro krrr krrs krrt krsk krsr krss krst krsu krtk krto krtr krts kruk krur ksbr ksbs kskb kskk ksko kskr ksks ksku ksob ksok ksoo ksor ksos ksou ksrb ksro ksrr ksrs ksrt ksso kssr ksss ksst kssu kstb kstk ksto kstr ksts kstt kstu ksub ksut ksuu ktbb ktbr ktbt ktbu ktkb ktkk ktko ktkr ktks ktkt ktku ktob ktok ktoo ktor ktot ktrb ktrk ktro ktrr ktrs ktrt ktru ktso ktsr ktst ktsu kttk ktto kttr ktts kttt kttu ktub kubb kubo kubr kubs kubu kukk kuks kuku kuok kuoo kuos kurb kurk kuro kurr kurs kurt kuru kusb kuso kust kusu kuto kutr kuts kutt kutu kuub kuuk kuur kuuu obbo obkb obok obor obos obot obro obsr obss obst obts obus okko okok okor okot okro okso okto okur okus ooku oooo ooos oort oost ootb oots oous orbb orbo orbs orbu orko oro- orok oror oros orot orro orrs orsk orso orsu orto orts orub orus osku osoo osor osos osro ossb osso ossu ostr osts otbs oto- otok otoo otor otos otro otrs otso otsu otto otts ottu otur otus oubs our- ouro ours ourt oust out- outb outo outs ouu- rbbb rbbr rbbs rbss rbst rkos rkss rkts rob- robb robo robs robt robu rokk roko rokr roks roku roob rook roor roos root rork roro rort roru roso ross rost rotk roto rotr rots rott roub rouk rous rout rrrr rsos rsts rstu rtss rtts rubb rubs rubu rukk ruku ruok ruro rurs ruru rusk ruso russ rust rusu ruto ruts rutt rutu s-os sbbs sbor sbot sbrk sbst sbtk sbus skor skot skrt skss skur skut sobo sobr sobs sobt sobu sokk soko soku sook soor soos soot sorb soro sorr sors sort soru soso soss sost sotk soto sots sotu souk sour sous sout sros srtr srub ssbr ssot ssrs sssb ssss sstb ssts stbs stks stob stok stoo stor stos stot stou strk stro strs stru stss sttr stub stuk stur stus stut sub- subb subo subs suks suku suor suos sur- suro surr surs surt suru sus- susk suso suss sust susu suto sutu suus tbbs tbrb tbst tkos tkts tobo tobs tobt tobu toko toku took toor toos toot tork toro torr tors tort toru tosb tosk toso toss tost tosu toto totr tots tott touk tour tous tout troo tros trot trou trst trtr trub truk trus trut truu tsks tsob tsos tsou tssr tsst tsts ttbb ttss tttt tubb tubo tubr tubs tubu tuko tuks tuor tuos turb turk turo turr turs turt turu tusk tuss tust tuto tuts tutt tutu tuuo ubbo ubos ukko ukok ukur uor- urbs uro- urok uroo urso urss ursu urts uruk