b-u bbb bbi bbs bbu bby bi- bib bii bis biu biy bsb bsi bss bsu bsy bub bui bus buu buy by- byi bys byu ibb ibi ibs ibu iby iib iii iis iiu is- isb isi iss isu isy iu- iub iui ius iys iyy sbb sbi sbs sbu sby sib sii sis siu ss- ssb ssi sss ssu sub sui sus suu suy sy- syb syi sys syu ubb ubi ubs ubu uby uib uii uis uiu usb usi uss usu uus uuu uyi uys uyu ybi ybs yby yii yis ysb ysi yss ysu ysy yui yus yuu yuy yyb yys yyu yyy