-er -ol bbb bbe bbi bbk bbl bbo bbr bbt be- beb bee bei bek bel beo ber bet bi- bib bie bii bik bil bio bir bit bkb bke bkk bkl bko bkr bkt blb ble bli blk bll blo blr blt bob boe boi bok bol boo bor bot brb bre bri brk brl bro brr brt btb bte bti btk btl bto btr btt ebb ebe ebi ebk ebl ebo ebr ebt eeb eee eek eel eeo eer eet eib eie eii eik eil eio eir eit ekb eke eki ekl eko ekr ekt elb ele eli elk ell elo elr elt eo- eob eoe eoi eok eol eoo eor eot erb ere eri erk erl ero err ert etb ete eti etk etl eto etr ett ibb ibe ibi ibk ibl ibo ibr ibt ie- iee iei iek iel ier iet iib iie iii iil iio iir iit ikb ike iki ikk ikl iko ikr ikt il- ilb ile ili ilk ill ilo ilr ilt io- iob ioe ioi iol ioo ior iot ir- irb ire iri irk irl iro irr irt itb ite iti itk itl ito itt k-t kbb kbe kbi kbk kbl kbo kbr ke- keb kee kei kek kel keo ker ket kib kie kii kik kil kio kir kit kkb kke kki kkk kkl kkr kkt kl- klb kli klo klr klt kob koe koi kok kol koo kor kot kri krk krl kro krr krt ktb kte ktk ktl kto ktr ktt lbb lbe lbi lbk lbl lbo lbr lbt leb lee lei lek lel leo ler let lib lie lii lik lil lio lir lit lkb lkl lkr lkt llb lle lli llk lll llo llr llt lob loe loi lok lol loo lor lot lrb lri lrk lro lrr lrt ltb lte lti ltk ltl lto ltr ltt o-i ob- obb obe obi obk obl obo obr obt oeb oee oei oel oeo oer oet oib oie oii oik oil oio oir oit okb oke oki okk okl oko okr olb ole oli olk oll olo olt oo- oob ooi ook ool ooo oor oot or- orb ore ori ork orl oro orr ort ot- otb ote oti otk otl oto otr ott rbb rbe rbi rbk rbl rbo rbr rbt re- reb ree rei rek rel reo rer ret rib rie rii rik ril rio rir rit rkb rke rkk rko rkt rle rli rll rlo rlr rlt rob roe roi rok rol roo ror rot rrb rri rrk rrl rrr rrt rtb rte rti rtk rtl rto rtr rtt tbb tbe tbi tbk tbl tbo tbr tbt te- teb tee tei tek tel teo ter tet tib tie tii tik til tio tir tit tkb tke tkk tkl tko tkr tkt tle tli tlk tll tlo tlr tlt to- tob toe toi tok tol too tor tot trb tre tri trk trl tro trr trt ttb tte tti ttk ttl tto ttr ttt