bbb bbc bbn bbo bbr bby bcb bcc bcn bco bcr bcy bcz bnb bnc bnn bno bnr bnz bob boc bon boo bor boy boz brb brn bro brr bry brz by- byc byn byo byr byz bzn bzo bzr bzz c-- cbb cbc cbn cbo cbr cby cbz ccb ccc ccn cco ccr ccz cn- cnb cnc cnn cno cnr cny co- cob coc con coo cor coy coz crb crc crn cro crr cry crz cyb cyc cyn cyo cyr cz- czc czo nbb nbc nbn nbo nbr ncb ncc ncn nco ncr nnb nnc nnn nno nnz no- nob noc non noo nor noy noz nrb nrc nrn nro nrr nry nrz nyc nyn nyo nyy nzb nzo nzz ob- obb obc obn obo obr oby oc- ocb occ ocn oco ocr ocz on- onb onc onn ono onr ony oo- oob ooc oon ooo oor or- orb orc orn oro orr ory orz oyo ozo ozz rbb rbc rbn rbo rbr rcb rcc rcn rco rcr rnb rnc rnn rno rnr rny rnz rob roc ron roo ror roy roz rrb rrc rrn rrr ry- ryc ryn ryo ryr ryy ryz rzb rzo rzy ybc ybr yby ybz ycc yco ycy ynn yny yob yoc yon yoo yor yoy yrc yrn yro yyb yyc yyy yyz yzb yzr yzy zbb zbc zbr zby zco znc znn zno zo- zob zoc zon zoo zor zro zzr zzy zzz