b-u bbb bbf bbi bbs bbu bfb bff bfi bfs bfu bi- bib bif bii bis biu bsb bsf bsi bss bsu bub buf bui bus buu fbb fbf fbi fbs fbu fff ffi ffs ffu fib fif fii fis fiu fsb fsf fsi fss fsu fub fuf fui fus fuu i-f ibb ibf ibi ibs ibu ifb iff ifi ifs ifu iib iif iii iis iiu is- isb isf isi iss isu iu- iub iui ius sbb sbf sbi sbs sbu sfb sff sfi sfs sfu sib sif sii sis siu ss- ssb ssf ssi sss ssu sub suf sui sus suu ubb ubf ubi ubs ubu uff ufi ufs ufu uib uif uii uis uiu usb usf usi uss usu uus uuu