b-u bbb bbk bbr bbu bby bkb bkk bkr brb brk brr bru bry brz bub buk bur buu buy buz by- byk byr byu byz bzr bzu bzz k-z kbb kbk kbr kbu kbz kkb kkk kkr kku kky krk krr kru kry kub kuk kur kuu kuy kyr kyu kyz kzy rbb rbk rbr rbu rkb rkk rku rky rkz rrb rrk rrr rru rub ruk rur ruu ruy ruz ry- ryk ryr ryu ryy ryz rzb rzy ubb ubk ubr ubu uby ukb ukk ukr uku ukz ur- urb urk urr uru ury urz uur uuu uyu uzb uzu ybr yby ybz ykk yru yuk yur yuu yuy yyb yyu yyy yyz yzb yzr yzu yzy zbb zbr zby zub zuk zur zuz zzr zzy zzz