bbb bbc bbo bbr bbt bby bcb bcc bco bcr bct bcy bob boc boo bor bot boy brb bro brr brt bry btb btc bto btr btt bty by- byc byo byr byt c-- cbb cbc cbo cbr cbt cby ccb ccc cco ccr cct co- cob coc coo cor cot coy crb crc cro crr crt cry ctb ctc cto ctr ctt cty cyb cyc cyo cyr cyt ob- obb obc obo obr obt oby oc- ocb occ oco ocr oct oo- oob ooc ooo oor oot or- orb orc oro orr ort ory ot- otb otc oto otr ott oyo rbb rbc rbo rbr rbt rcb rcc rco rcr rct rob roc roo ror rot roy rrb rrc rrr rrt rtb rtc rto rtr rtt rty ry- ryc ryo ryr ryy tbb tbc tbo tbr tbt tcb tcc tco tcr tct to- tob toc too tor tot toy trb trc tro trr trt try ttb ttc tto ttr ttt tty tyc tyo tyr tyt ybc ybr yby ycc yco ycy yob yoc yoo yor yot yoy yrc yro yrt ytc yto ytr ytt yyb yyc yyt yyy