b-p bbb bbn bbo bbp bbs bnb bnn bno bnp bns bob bon boo bop bos bpb bpn bpo bpp bps bsb bsn bso bsp bss nbb nbn nbo nbp nbs nnb nnn nno nnp nns no- nob non noo nop nos npb npn npo npp nps nsb nsn nso nsp nss ob- obb obn obo obp obs on- onb onn ono onp ons oo- oob oon ooo oop oos op- opb opn opo opp ops os- osb osn oso osp oss p-p pbb pbn pbo pbp pbs pn- pnb pnn pno pnp pns pob pon poo pop pos ppb ppn ppo ppp pps ps- psb psn pso psp pss sbb sbn sbo sbp sbs snb snn sno snp sns sob son soo sop sos spb spn spo spp sps ss- ssb ssn sso ssp sss