b-u bbb bbf bbi bbs bbu bbx bfb bff bfi bfs bfu bfx bi- bib bif bii bis biu bix bsb bsf bsi bss bsu bsx bub buf bui bus buu bux bxb bxi bxx fbb fbf fbi fbs fbu fbx fff ffi ffs ffu ffx fib fif fii fis fiu fix fsb fsf fsi fss fsu fsx fub fuf fui fus fuu fux fxi fxs fxu fxx i-f ibb ibf ibi ibs ibu ibx ifb iff ifi ifs ifu ifx iib iif iii iis iiu iix is- isb isf isi iss isu iu- iub iui ius ixi sbb sbf sbi sbs sbu sbx sfb sff sfi sfs sfu sfx sib sif sii sis siu six ss- ssb ssf ssi sss ssu ssx sub suf sui sus suu sux sxi sxs sxu ubb ubf ubi ubs ubu ubx uff ufi ufs ufu ufx uib uif uii uis uiu usb usf usi uss usu usx uus uuu uxb uxf uxu xbx xfs xfx xii xis xiu xix xsb xsi xss xui xus xxi xxx