-er -ol bbb bbe bbk bbl bbo bbr be- beb bee bek bel beo ber bkb bke bkk bkl bko bkr blb ble blk bll blo blr bob boe bok bol boo bor brb bre brk brl bro brr ebb ebe ebk ebl ebo ebr eeb eee eek eel eeo eer ekb eke ekl eko ekr elb ele elk ell elo elr eo- eob eoe eok eol eoo eor erb ere erk erl ero err kbb kbe kbk kbl kbo kbr ke- keb kee kek kel keo ker kkb kke kkk kkl kkr kl- klb klo klr kob koe kok kol koo kor krk krl kro krr lbb lbe lbk lbl lbo lbr leb lee lek lel leo ler lkb lkl lkr llb lle llk lll llo llr lob loe lok lol loo lor lrb lrk lro lrr ob- obb obe obk obl obo obr oeb oee oel oeo oer okb oke okk okl oko okr olb ole olk oll olo oo- oob ook ool ooo oor or- orb ore ork orl oro orr rbb rbe rbk rbl rbo rbr re- reb ree rek rel reo rer rkb rke rkk rko rle rll rlo rlr rob roe rok rol roo ror rrb rrk rrl rrr