b-u bbb bbi bbr bbt bbu bby bi- bib bii bir bit biu biy biz brb bri brr brt bru bry brz btb bti btr btt btu bty btz bub bui bur but buu buy buz by- byi byr byt byu byz bzr bzu bzz ibb ibi ibr ibt ibu iby ibz iib iii iir iit iiu ir- irb iri irr irt iru iry itb iti itt itu ity itz iu- iub iui iur iut iuz iyr iyt iyy izi izu izy izz rbb rbi rbr rbt rbu rib rii rir rit riy riz rrb rri rrr rrt rru rtb rti rtr rtt rtu rty rtz rub rui rur rut ruu ruy ruz ry- ryr ryu ryy ryz rzb rzy tbb tbi tbr tbt tbu tbz tib tii tir tit tiu tiy tiz trb tri trr trt tru try trz ttb tti ttr ttt ttu tty tub tui tur tut tuu tuy tuz tyr tyt tzu ubb ubi ubr ubt ubu uby uib uii uir uit uiu ur- urb uri urr urt uru ury urz utb uti utr utt utu uty utz uur uut uuu uyi uyu uzb uzi uzu ybi ybr yby ybz yii yir yit yiz yrt yru ytr ytt ytu yui yur yut yuu yuy yyb yyt yyu yyy yyz yzb yzr yzu yzy zbb zbr zbt zby zib zir zit ziz ztr zub zui zur zut zuz zzr zzt zzy zzz