b-u bbb bbi bbk bbr bbu bi- bib bii bik bir biu biv bkb bkk bkr bkv brb bri brk brr bru brv bub bui buk bur buu bvb bvi bvk bvr bvu bvv i-v ibb ibi ibk ibr ibu ibv iib iii iir iiu ikb iki ikk ikr iku ikv ir- irb iri irk irr iru irv iu- iub iui iur ivb ivi ivr ivu ivv kbb kbi kbk kbr kbu kib kii kik kir kiu kiv kkb kki kkk kkr kku kkv kri krk krr kru krv kub kui kuk kur kuu kvb kvi kvk kvr kvv rbb rbi rbk rbr rbu rib rii rik rir riv rkb rkk rku rkv rrb rri rrk rrr rru rub rui ruk rur ruu ruv rvb rvi rvr rvu rvv ubb ubi ubk ubr ubu ubv uib uii uir uiu ukb uki ukk ukr uku ur- urb uri urk urr uru uur uuu uvb uvu uvv vbi vbk vbr vbv vi- vib vii vik vir viu viv vkb vrb vri vrk vrr vru vuk vur vuv vvb vvi vvr vvv