b-p bbb bbi bbk bbp bbs bby bi- bib bii bik bip bis biy bkb bkk bkp bks bpb bpi bpp bps bpy bsb bsi bsk bsp bss bsy by- byi byk byp bys ibb ibi ibk ibp ibs iby iib iii iip iis ikb iki ikk iks ipb ipi ipp ips ipy is- isb isi isk isp iss isy iys iyy kbb kbi kbk kbp kbs kib kii kik kip kis kkb kki kkk kkp kks kky kpi kpk kpp kps ksb ksi ksk ksp kss kyp kys p-p pbb pbi pbk pbp pbs pby pib pii pik pip pis pkb pki pkp pks pky ppb ppi ppk ppp pps ps- psb psi psk psp pss psy py- pyb pyk pys sbb sbi sbk sbp sbs sby sib sii sik sip sis sk- skb ski skk skp sks sky spb spi spk spp sps spy ss- ssb ssi ssk ssp sss sy- syb syi syk syp sys ybi ybp ybs yby yii yip yis yki ykk yps ysb ysi ysk ysp yss ysy yyb yys yyy