-er -ol bbb bbe bbl bbo bbr bbt be- beb bee bel beo ber bet blb ble bll blo blr blt bob boe bol boo bor bot brb bre brl bro brr brt btb bte btl bto btr btt ebb ebe ebl ebo ebr ebt eeb eee eel eeo eer eet elb ele ell elo elr elt eo- eob eoe eol eoo eor eot erb ere erl ero err ert etb ete etl eto etr ett lbb lbe lbl lbo lbr lbt leb lee lel leo ler let llb lle lll llo llr llt lob loe lol loo lor lot lrb lro lrr lrt ltb lte ltl lto ltr ltt ob- obb obe obl obo obr obt oeb oee oel oeo oer oet olb ole oll olo olt oo- oob ool ooo oor oot or- orb ore orl oro orr ort ot- otb ote otl oto otr ott rbb rbe rbl rbo rbr rbt re- reb ree rel reo rer ret rle rll rlo rlr rlt rob roe rol roo ror rot rrb rrl rrr rrt rtb rte rtl rto rtr rtt tbb tbe tbl tbo tbr tbt te- teb tee tel teo ter tet tle tll tlo tlr tlt to- tob toe tol too tor tot trb tre trl tro trr trt ttb tte ttl tto ttr ttt