b-u bbb bbc bbk bbo bbr bbs bbu bcb bcc bck bco bcr bcs bcu bkb bkc bkk bko bkr bks bob boc bok boo bor bos bou brb brk bro brr brs bru bsb bsc bsk bso bsr bss bsu bub buc buk buo bur bus buu c-- cbb cbc cbk cbo cbr cbs cbu ccb ccc cck cco ccr ccs ccu ckb ckc cko cks co- cob coc cok coo cor cos cou crb crc crk cro crr crs cru csb csc csk cso csr css csu cub cuc cuk cuo cur cus cuu kbb kbc kbk kbo kbr kbs kbu kcb kcc kck kcr kcs kcu kkb kkc kkk kkr kks kku kob koc kok koo kor kos kou krc krk kro krr krs kru ksb ksc ksk kso ksr kss ksu kub kuc kuk kur kus kuu ob- obb obc obk obo obr obs obu oc- ocb occ ock oco ocr ocs ocu okb okc okk oko okr oks oku oo- oob ooc ook ooo oor oos or- orb orc ork oro orr ors oru os- osb osc osk oso osr oss osu ou- ouc ouk ouo our ous rbb rbc rbk rbo rbr rbs rbu rcb rcc rco rcr rcs rcu rkb rkc rkk rko rks rku rob roc rok roo ror ros rou rrb rrc rrk rrr rrs rru rsb rsc rsk rso rsr rss rsu rub ruc ruk ruo rur rus ruu sbb sbc sbk sbo sbr sbs sbu scb scc sck sco scr scs scu sk- skb skc skk sko skr sks sku sob soc sok soo sor sos sou sr- srb src srk sro srr srs ss- ssb ssc ssk sso ssr sss ssu sub suc suk suo sur sus suu ubb ubc ubk ubo ubr ubs ubu ucb ucc uck uco ucr ucs ucu ukb ukc ukk ukr uku uob uoc uok uoo uor uos ur- urb urc urk uro urr urs uru usb usc usk uso usr uss usu uuc uur uus uuu

-ous bbbb bbbs bbrc bcbc bcbs bccc bccs bcor bcos bcrs bcru bcsc bcss bcuc bobb bobo bobs bobu bock boco bocs bocu boko boks boku boob booc book boor boos bor- bork boro borr bors boru bosc bosk boso boss bosu bouk bour bous brcb brkb brob broc brok broo bror bros brou brrr brrs brsb brsr bruc brus bscs bsos bssc bubb bubo bubs bubu bucc buck buco bucs bucu bukk buko buku bur- burb burk buro burr burs buru busc busk buss busu buus c-bo cbbc cbbs cbcc cbcr cbcs cbcu cbko cbkr cbsc cbus ccbc cccb cccc cccs cccu ccob ccoc ccrc ccrs ccss ccuc ccus ckbc ckck ckco ckcs ckob ckoc ckoo ckor ckos ckrc cksb ckso cobb cobo cobs cobu cock coco cocu cok- coko coob cook coos cor- corb corc cork coro corr cors cosc coso coss coub couk cour cous crbc crbu crcc crcr crkc crob croc crok croo cror crss crub cruk crus cscb cscc csco cscr cscs csks csob csor csos csrc csrs cssr csur csus cub- cubb cubs cucc cuck cuk- curb curo curr curs cusb cusk cuso cuss cusu k-os kbbb kbbc kbbk kbbo kbbr kbbs kbbu kbcb kbck kbco kbcr kbcs kbcu kbkb kbkk kbko kbkr kbob kboc kbok kboo kbos kbrb kbrc kbrk kbro kbru kbsb kbsk kbso kbsr kbss kbsu kbub kbuc kbuk kbur kbus kbuu kcbc kcbk kcbr kcbs kcbu kccb kccc kcck kccr kccu kckc kckk kcko kckr kcob kcor kcos kcou kcrc kcro kcrr kcrs kcru kcsb kcsc kcsr kcss kcsu kcub kcuk kkbb kkbo kkbr kkbs kkcb kkck kkco kkcr kkcs kkkk kkob kkoo kkor kkrb kkrc kkrk kkro kkrr kkrs kksr kkss kksu kkus kkuu kobb kobc kobk kobo kobr kobs kobu kocb kock kocs kokb kokc kokk koko kokr koks koku koob kooc kook kooo koor koos koou korb korc kork koro korr kors koru kos- kosb kosc koso kosr koss kosu koub kour kous kouu krbb krbk krbr krcb krcc krco krcs krcu krkc krkk krko krkr krks krku krob kroc krok kroo kror kros krrb krrc krrk krro krrr krrs krsc krsk krsr krss krsu kruc kruk krur ksbc ksbr ksbs kscb ksck ksco kscr kscs kscu kskb kskk ksko kskr ksks ksku ksob ksoc ksok ksoo ksor ksos ksou ksrb ksro ksrr ksrs ksso kssr ksss kssu ksub ksuu kubb kubc kubo kubr kubs kubu kucb kucc kuco kucr kukk kuks kuku kuok kuoo kuos kurb kurk kuro kurr kurs kuru kusb kusc kuso kusu kuub kuuk kuur kuuu obbo obkb obok obor obos obro obsr obss obus ocbc occc ocks ocos ocro ocrr ocrs ocur okcu okko okok okor okro okso okur okus oocr ooku oooo ooos oous orbb orbo orbs orbu orco orcs orko oro- orok oror oros orro orrs orsk orso orsu orub orus oscc osco osku osoo osor osos osro ossb osso ossu oubs oucc our- ouro ours ouu- rbbb rbbr rbbs rbss rcbc rcbo rccb rccc rccs rcos rcsc rcss rkos rkss rob- robb robo robs robu rocc rock roco rocs rokk roko rokr roks roku roob rook roor roos rorc rork roro roru rosc roso ross roub rouk rous rrrr rscc rscs rsos rubb rubs rubu ruck rukk ruku ruok rurc ruro rurs ruru rusk ruso russ rusu s-os sbbs sbcc sbcs sbor sbrk sbus sccc sccs sck- scob scok scoo scor scr- scrc scrs scsc scso scsr scsu scub scur skor skss skur sobo sobr sobs sobu sock soco socr socs sokk soko soku sook soor soos sorb soro sorr sors soru soso soss souk sour sous srbc srcc sros srub ssbr sscc sscs ssoc ssrc ssrs sssb sssc ssss sub- subb subo subs suc- succ suck sucr sucs suks suku suor suos sur- surc suro surr surs suru sus- susk suso suss susu suus ubbo uboc ubos ucbc ucos ucrc ucsb ucsc ucsu ukcc ukko ukok ukrc uksc ukur uocc uor- urbs uro- urok uroo urso urss ursu uruk urur urus us-k usbc usbr