bbbb bbrc bcbc bccc bcor bcru bcuc bobb bobo bobu bock boco bocu boko boku boob booc book boor bor- bork boro borr boru bouk bour brcb brkb brob broc brok broo bror brou brrr bruc bubb bubo bubu bucc buck buco bucu bukk buko buku bur- burb burk buro burr buru c-bo cbbc cbcc cbcr cbcu cbko cbkr ccbc cccb cccc cccu ccob ccoc ccrc ccuc ckbc ckck ckco ckob ckoc ckoo ckor ckrc cobb cobo cobu cock coco cocu cok- coko coob cook cor- corb corc cork coro corr coub couk cour crbc crbu crcc crcr crkc crob croc crok croo cror crub cruk cub- cubb cucc cuck cuk- curb curo curr kbbb kbbc kbbk kbbo kbbr kbbu kbcb kbck kbco kbcr kbcu kbkb kbkk kbko kbkr kbob kboc kbok kboo kbrb kbrc kbrk kbro kbru kbub kbuc kbuk kbur kbuu kcbc kcbk kcbr kcbu kccb kccc kcck kccr kccu kckc kckk kcko kckr kcob kcor kcou kcrc kcro kcrr kcru kcub kcuk kkbb kkbo kkbr kkcb kkck kkco kkcr kkkk kkob kkoo kkor kkrb kkrc kkrk kkro kkrr kkuu kobb kobc kobk kobo kobr kobu kocb kock kokb kokc kokk koko kokr koku koob kooc kook kooo koor koou korb korc kork koro korr koru koub kour kouu krbb krbk krbr krcb krcc krco krcu krkc krkk krko krkr krku krob kroc krok kroo kror krrb krrc krrk krro krrr kruc kruk krur kubb kubc kubo kubr kubu kucb kucc kuco kucr kukk kuku kuok kuoo kurb kurk kuro kurr kuru kuub kuuk kuur kuuu obbo obkb obok obor obro ocbc occc ocro ocrr ocur okcu okko okok okor okro okur oocr ooku oooo orbb orbo orbu orco orko oro- orok oror orro orub oucc our- ouro ouu- rbbb rbbr rcbc rcbo rccb rccc rob- robb robo robu rocc rock roco rokk roko rokr roku roob rook roor rorc rork roro roru roub rouk rrrr rubb rubu ruck rukk ruku ruok rurc ruro ruru ubbo uboc ucbc ucrc ukcc ukko ukok ukrc ukur uocc uor- uro- urok uroo uruk urur uuoc uuuu