b-p bbb bbn bbo bbp bbr bbs bnb bnn bno bnp bnr bns bob bon boo bop bor bos bpb bpn bpo bpp bpr bps brb brn bro brp brr brs bsb bsn bso bsp bsr bss nbb nbn nbo nbp nbr nbs nnb nnn nno nnp nns no- nob non noo nop nor nos npb npn npo npp npr nps nrb nrn nro nrp nrr nrs nsb nsn nso nsp nsr nss ob- obb obn obo obp obr obs on- onb onn ono onp onr ons oo- oob oon ooo oop oor oos op- opb opn opo opp opr ops or- orb orn oro orp orr ors os- osb osn oso osp osr oss p-p pbb pbn pbo pbp pbr pbs pn- pnb pnn pno pnp pnr pns pob pon poo pop por pos ppb ppn ppo ppp ppr pps prb prn pro prp prr prs ps- psb psn pso psp psr pss rbb rbn rbo rbp rbr rbs rnb rnn rno rnp rnr rns rob ron roo rop ror ros rpb rpn rpo rpp rpr rps rrb rrn rrp rrr rrs rsb rsn rso rsp rsr rss sbb sbn sbo sbp sbr sbs snb snn sno snp snr sns sob son soo sop sor sos spb spn spo spp spr sps sr- srb srn sro srp srr srs ss- ssb ssn sso ssp ssr sss