bbb bbr bbs bbt bby brb brr brs brt bry brz bsb bsr bss bst bsy btb btr bts btt bty btz by- byr bys byt byz bzr bzs bzz rbb rbr rbs rbt rrb rrr rrs rrt rsb rsr rss rst rtb rtr rts rtt rty rtz ry- ryr rys ryy ryz rzb rzy sbb sbr sbs sbt sby sr- srb srr srs srt sry ss- ssb ssr sss sst ssz stb str sts stt sty stz sy- syb syr sys syt szr tbb tbr tbs tbt tbz trb trr trs trt try trz tsb tsr tss tst tsy ttb ttr tts ttt tty tyr tys tyt tzs ybr ybs yby ybz yrs yrt ysb ysr yss yst ysy ysz ytr yts ytt yyb yys yyt yyy yyz yzb yzr yzy zbb zbr zbs zbt zby zrs zst zsz ztr zzr zzs zzt zzy zzz