bbb bbi bbo bbs bby bi- bib bii bio bis biy bob boi boo bos boy bsb bsi bso bss bsy by- byi byo bys ibb ibi ibo ibs iby iib iii iio iis io- iob ioi ioo ios is- isb isi iso iss isy iyo iys iyy o-i ob- obb obi obo obs oby oib oii oio ois oo- oob ooi ooo oos os- osb osi oso oss oyi oyo oys sbb sbi sbo sbs sby sib sii sio sis sob soi soo sos soy ss- ssb ssi sso sss sy- syb syi sys ybi ybs yby yii yio yis yob yoi yoo yos yoy ysb ysi yso yss ysy yyb yys yyy