b-p bbb bbc bbn bbo bbp bbr bbs bcb bcc bcn bco bcp bcr bcs bnb bnc bnn bno bnp bnr bns bob boc bon boo bop bor bos bpb bpc bpn bpo bpp bpr bps brb brn bro brp brr brs bsb bsc bsn bso bsp bsr bss c-- cbb cbc cbn cbo cbp cbr cbs ccb ccc ccn cco ccp ccr ccs cn- cnb cnc cnn cno cnp cnr cns co- cob coc con coo cop cor cos cpb cpc cpn cpo cpp cpr cps crb crc crn cro crp crr crs csb csc csn cso csp csr css nbb nbc nbn nbo nbp nbr nbs ncb ncc ncn nco ncp ncr ncs nnb nnc nnn nno nnp nns no- nob noc non noo nop nor nos npb npc npn npo npp npr nps nrb nrc nrn nro nrp nrr nrs nsb nsc nsn nso nsp nsr nss ob- obb obc obn obo obp obr obs oc- ocb occ ocn oco ocp ocr ocs on- onb onc onn ono onp onr ons oo- oob ooc oon ooo oop oor oos op- opb opc opn opo opp opr ops or- orb orc orn oro orp orr ors os- osb osc osn oso osp osr oss p-p pbb pbc pbn pbo pbp pbr pbs pcb pcc pcn pco pcp pcr pcs pn- pnb pnc pnn pno pnp pnr pns pob poc pon poo pop por pos ppb ppc ppn ppo ppp ppr pps prb prc prn pro prp prr prs ps- psb psc psn pso psp psr pss rbb rbc rbn rbo rbp rbr rbs rcb rcc rcn rco rcp rcr rcs rnb rnc rnn rno rnp rnr rns rob roc ron roo rop ror ros rpb rpc rpn rpo rpp rpr rps rrb rrc rrn rrp rrr rrs rsb rsc rsn rso rsp rsr rss sbb sbc sbn sbo sbp sbr sbs scb scc scn sco scp scr scs snb snc snn sno snp snr sns sob soc son soo sop sor sos spb spc spn spo spp spr sps sr- srb src srn sro srp srr srs ss- ssb ssc ssn sso ssp ssr sss