b-p bbb bbi bbn bbo bbp bbr bbs bi- bib bii bin bio bip bir bis bnb bni bnn bno bnp bnr bns bob boi bon boo bop bor bos bpb bpi bpn bpo bpp bpr bps brb bri brn bro brp brr brs bsb bsi bsn bso bsp bsr bss ibb ibi ibn ibo ibp ibr ibs iib iii iin iio iip iir iis in- inb ini inn ino inp inr ins io- iob ioi ion ioo iop ior ios ipb ipi ipn ipo ipp ipr ips ir- irb iri irn iro irp irr irs is- isb isi isn iso isp isr iss n-i nbb nbi nbn nbo nbp nbr nbs nib nii nin nio nip nir nis nnb nni nnn nno nnp nns no- nob noi non noo nop nor nos npb npi npn npo npp npr nps nrb nri nrn nro nrp nrr nrs nsb nsi nsn nso nsp nsr nss o-i ob- obb obi obn obo obp obr obs oib oii oin oio oip oir ois on- onb oni onn ono onp onr ons oo- oob ooi oon ooo oop oor oos op- opb opi opn opo opp opr ops or- orb ori orn oro orp orr ors os- osb osi osn oso osp osr oss p-p pbb pbi pbn pbo pbp pbr pbs pib pii pin pio pip pir pis pn- pnb pni pnn pno pnp pnr pns pob poi pon poo pop por pos ppb ppi ppn ppo ppp ppr pps prb pri prn pro prp prr prs ps- psb psi psn pso psp psr pss rbb rbi rbn rbo rbp rbr rbs rib rii rin rio rip rir ris rnb rni rnn rno rnp rnr rns rob roi ron roo rop ror ros rpb rpi rpn rpo rpp rpr rps rrb rri rrn rrp rrr rrs rsb rsi rsn rso rsp rsr rss sbb sbi sbn sbo sbp sbr sbs sib sii sin sio sip sir sis snb sni snn sno snp snr sns sob soi son soo sop sor sos spb spi spn spo spp spr sps sr- srb sri srn sro srp srr srs ss- ssb ssi ssn sso ssp ssr sss