bbb bbc bbk bbo bbr bbs bby bcb bcc bck bco bcr bcs bcy bcz bkb bkc bkk bko bkr bks bob boc bok boo bor bos boy boz brb brk bro brr brs bry brz bsb bsc bsk bso bsr bss bsy by- byc byk byo byr bys byz bzo bzr bzs bzz c-- cbb cbc cbk cbo cbr cbs cby cbz ccb ccc cck cco ccr ccs ccz ckb ckc cko cks cky co- cob coc cok coo cor cos coy coz crb crc crk cro crr crs cry crz csb csc csk cso csr css csy csz cyb cyc cyk cyo cyr cys cz- czc czk czo k-z kbb kbc kbk kbo kbr kbs kbz kcb kcc kck kcr kcs kkb kkc kkk kkr kks kky kob koc kok koo kor kos koy koz krc krk kro krr krs kry ksb ksc ksk kso ksr kss kyc kyo kyr kys kyz kzo kzy ob- obb obc obk obo obr obs oby oc- ocb occ ock oco ocr ocs ocz okb okc okk oko okr oks oo- oob ooc ook ooo oor oos or- orb orc ork oro orr ors ory orz os- osb osc osk oso osr oss oyo oys ozo ozs ozz rbb rbc rbk rbo rbr rbs rcb rcc rco rcr rcs rkb rkc rkk rko rks rky rkz rob roc rok roo ror ros roy roz rrb rrc rrk rrr rrs rsb rsc rsk rso rsr rss ry- ryc ryk ryo ryr rys ryy ryz rzb rzo rzy sbb sbc sbk sbo sbr sbs sby scb scc sck sco scr scs sk- skb skc skk sko skr sks sky sob soc sok soo sor sos soy soz sr- srb src srk sro srr srs sry ss- ssb ssc ssk sso ssr sss ssz sy- syb syc syk syr sys szr ybc ybr ybs yby ybz ycc yco ycs ycy ykk yob yoc yok yoo yor yos yoy yrc yro yrs ysb ysc ysk yso ysr yss ysy ysz yyb yyc yys yyy yyz yzb yzr yzy zbb zbc zbr zbs zby zco zcs zks zo- zob zoc zok zoo zor zos zro zrs zsz zzr zzs zzy zzz