-er -ol b-u bbb bbe bbk bbl bbo bbr bbu be- beb bee bek bel beo ber beu bev bkb bke bkk bkl bko bkr bkv blb ble blk bll blo blr blu blv bob boe bok bol boo bor bou bov brb bre brk brl bro brr bru brv bub bue buk bul buo bur buu bvb bve bvk bvl bvo bvr bvu bvv ebb ebe ebk ebl ebo ebr ebu ebv eeb eee eek eel eeo eer eev ekb eke ekl eko ekr eku ekv elb ele elk ell elo elr elu elv eo- eob eoe eok eol eoo eor eou erb ere erk erl ero err eru erv eu- eub eue eul eur euv evb eve evl evo evr evv kbb kbe kbk kbl kbo kbr kbu ke- keb kee kek kel keo ker kev kkb kke kkk kkl kkr kku kkv kl- klb klo klr klu klv kob koe kok kol koo kor kou krk krl kro krr kru krv kub kue kuk kul kur kuu kvb kvk kvo kvr kvv lbb lbe lbk lbl lbo lbr lbu lbv leb lee lek lel leo ler leu lev lkb lkl lkr llb lle llk lll llo llr llu llv lob loe lok lol loo lor lou lov lrb lrk lro lrr lru lrv lub lue luk lul luo lur luu luv lvb lve lvl lvr lvv ob- obb obe obk obl obo obr obu obv oeb oee oel oeo oer okb oke okk okl oko okr oku olb ole olk oll olo olu oo- oob ook ool ooo oor oov or- orb ore ork orl oro orr oru orv ou- oue ouk oul ouo our ov- ovb ove ovl ovo ovv rbb rbe rbk rbl rbo rbr rbu re- reb ree rek rel reo rer reu rev rkb rke rkk rko rku rkv rle rll rlo rlr rlu rob roe rok rol roo ror rou rov rrb rrk rrl rrr rru rub rue ruk ruo rur ruu ruv rvb rve rvl rvo rvr rvu rvv ubb ube ubk ubl ubo ubr ubu ubv ueb uee uel uer ukb uke ukk ukl ukr uku ulb ule ulk ull ulo ulr ulu ulv uob uoe uok uol uoo uor ur- urb ure urk url uro urr uru uue uur uuu uvb uve uvl uvo uvu uvv v-e vbk vbl vbo vbr vbv veb vee vek vel veo ver veu vkb vl- vlb vle vlk vll vlo vlv vob voe vok vol voo vor vou vov vrb vre vrk vrr vru vue vuk vul vur vuv vvb vvo vvr vvv