bbb bbk bbo bbr bbs bbt bby bkb bkk bko bkr bks bkt bob bok boo bor bos bot boy brb brk bro brr brs brt bry bsb bsk bso bsr bss bst bsy btb btk bto btr bts btt bty by- byk byo byr bys byt k-t kbb kbk kbo kbr kbs kkb kkk kkr kks kkt kky kob kok koo kor kos kot koy krk kro krr krs krt kry ksb ksk kso ksr kss kst ktb ktk kto ktr kts ktt kyo kyr kys kyt ob- obb obk obo obr obs obt oby okb okk oko okr oks oo- oob ook ooo oor oos oot or- orb ork oro orr ors ort ory os- osb osk oso osr oss ost ot- otb otk oto otr ots ott oyo oys rbb rbk rbo rbr rbs rbt rkb rkk rko rks rkt rky rob rok roo ror ros rot roy rrb rrk rrr rrs rrt rsb rsk rso rsr rss rst rtb rtk rto rtr rts rtt rty ry- ryk ryo ryr rys ryy sbb sbk sbo sbr sbs sbt sby sk- skb skk sko skr sks skt sky sob sok soo sor sos sot soy sr- srb srk sro srr srs srt sry ss- ssb ssk sso ssr sss sst stb stk sto str sts stt sty sy- syb syk syr sys syt tbb tbk tbo tbr tbs tbt tkb tkk tko tkr tks tkt tky to- tob tok too tor tos tot toy trb trk tro trr trs trt try tsb tsk tso tsr tss tst tsy ttb ttk tto ttr tts ttt tty tyo tyr tys tyt ybr ybs yby ykk yob yok yoo yor yos yot yoy yro yrs yrt ysb ysk yso ysr yss yst ysy ytk yto ytr yts ytt yyb yys yyt yyy