b-p bbb bbi bbk bbo bbp bbs bi- bib bii bik bio bip bis bkb bkk bko bkp bks bob boi bok boo bop bos bpb bpi bpo bpp bps bsb bsi bsk bso bsp bss ibb ibi ibk ibo ibp ibs iib iii iio iip iis ikb iki ikk iko iks io- iob ioi ioo iop ios ipb ipi ipo ipp ips is- isb isi isk iso isp iss kbb kbi kbk kbo kbp kbs kib kii kik kio kip kis kkb kki kkk kkp kks kob koi kok koo kop kos kpi kpk kpo kpp kps ksb ksi ksk kso ksp kss o-i ob- obb obi obk obo obp obs oib oii oik oio oip ois okb oki okk oko okp oks oo- oob ooi ook ooo oop oos op- opb opi opk opo opp ops os- osb osi osk oso osp oss p-p pbb pbi pbk pbo pbp pbs pib pii pik pio pip pis pkb pki pko pkp pks pob poi pok poo pop pos ppb ppi ppk ppo ppp pps ps- psb psi psk pso psp pss sbb sbi sbk sbo sbp sbs sib sii sik sio sip sis sk- skb ski skk sko skp sks sob soi sok soo sop sos spb spi spk spo spp sps ss- ssb ssi ssk sso ssp sss