b-p bbb bbo bbp bbr bbs bby bob boo bop bor bos boy bpb bpo bpp bpr bps bpy brb bro brp brr brs bry bsb bso bsp bsr bss bsy by- byo byp byr bys ob- obb obo obp obr obs oby oo- oob ooo oop oor oos op- opb opo opp opr ops opy or- orb oro orp orr ors ory os- osb oso osp osr oss oyo oys p-p pbb pbo pbp pbr pbs pby pob poo pop por pos poy ppb ppo ppp ppr pps prb pro prp prr prs pry ps- psb pso psp psr pss psy py- pyb pyo pyr pys rbb rbo rbp rbr rbs rob roo rop ror ros roy rpb rpo rpp rpr rps rrb rrp rrr rrs rsb rso rsp rsr rss ry- ryo ryr rys ryy sbb sbo sbp sbr sbs sby sob soo sop sor sos soy spb spo spp spr sps spy sr- srb sro srp srr srs sry ss- ssb sso ssp ssr sss sy- syb syp syr sys ybp ybr ybs yby yob yoo yop yor yos yoy ypo yps yro yrp yrs ysb yso ysp ysr yss ysy yyb yys yyy