b-p bbb bbi bbo bbp bbs bby bi- bib bii bio bip bis biy bob boi boo bop bos boy bpb bpi bpo bpp bps bpy bsb bsi bso bsp bss bsy by- byi byo byp bys ibb ibi ibo ibp ibs iby iib iii iio iip iis io- iob ioi ioo iop ios ipb ipi ipo ipp ips ipy is- isb isi iso isp iss isy iyo iys iyy o-i ob- obb obi obo obp obs oby oib oii oio oip ois oo- oob ooi ooo oop oos op- opb opi opo opp ops opy os- osb osi oso osp oss oyi oyo oys p-p pbb pbi pbo pbp pbs pby pib pii pio pip pis pob poi poo pop pos poy ppb ppi ppo ppp pps ps- psb psi pso psp pss psy py- pyb pyo pys sbb sbi sbo sbp sbs sby sib sii sio sip sis sob soi soo sop sos soy spb spi spo spp sps spy ss- ssb ssi sso ssp sss sy- syb syi syp sys ybi ybp ybs yby yii yio yip yis yob yoi yoo yop yos yoy ypo yps ysb ysi yso ysp yss ysy yyb yys yyy