bbbb bbrc bcbc bccc bcor bctc bobb bobo bock boco boko boob booc book boor boot bor- bork boro borr bort botb boto bott brcb brkb brob broc brok broo bror brot brrr brtc btcc btob btor btrc btrt bttb c-bo cbbc cbcc cbcr cbct cbko cbkr cbot cbrt cbtc ccbc cccb cccc ccob ccoc ccrc ccrt cctb cctc cctt ckbc ckck ckco ckob ckoc ckoo ckor ckot ckrc cktb cobb cobo cock coco coct cok- coko coob cook coot cor- corb corc cork coro corr cort cotb cotc coto cott crbc crcc crcr crkc crob croc crok croo cror crot crrt crtc ctor ctot ctrc kbbb kbbc kbbk kbbo kbbr kbbt kbcb kbck kbco kbcr kbct kbkb kbkk kbko kbkr kbob kboc kbok kboo kbot kbrb kbrc kbrk kbro kbrt kbtb kbtc kbtk kbto kbtr kbtt kcbc kcbk kcbr kccb kccc kcck kccr kcct kckc kckk kcko kckr kcob kcor kcot kcrc kcro kcrr kcrt kctb kctc kcto kkbb kkbo kkbr kkbt kkcb kkck kkco kkcr kkct kkkk kkob kkoo kkor kkot kkrb kkrc kkrk kkro kkrr kkrt kktc kktk kobb kobc kobk kobo kobr kocb kock koct kokb kokc kokk koko kokr koob kooc kook kooo koor koot korb korc kork koro korr kort kotb kotc kotk koto kotr kott krbb krbk krbr krbt krcb krcc krco krkc krkk krko krkr krob kroc krok kroo kror krrb krrc krrk krro krrr krrt krtc krtk krto krtr ktbb ktbc ktbr ktbt ktcc ktck ktco ktcr ktkb ktkc ktkk ktko ktkr ktkt ktob ktoc ktok ktoo ktor ktot ktrb ktrc ktrk ktro ktrr ktrt kttc kttk ktto kttr kttt obbo obkb obok obor obot obro ocbc occc occt ocro ocrr oct- octo okko okok okor okot okro okto oocr oooo oort ootb orbb orbo orco orko oro- orok oror orot orro ortc orto oto- otok otoo otor otro otto rbbb rbbr rcbc rcbo rccb rccc rctc rob- robb robo robt rocc rock roco rokk roko rokr roob rook roor root rorc rork roro rort rotc rotk roto rotr rott rrrr rtcc tbcb tbcc tbrb tccc tctc tobo tobt tock toco toko took toor toot torc tork toro torr tort totc toto totr tott trcc troc troo trot trtc trtr ttbb tttt