-er -ol bbb bbe bbl bbo bbr bbs bbt be- beb bee bel beo ber bes bet blb ble bll blo blr bls blt bob boe bol boo bor bos bot brb bre brl bro brr brs brt bsb bse bsl bso bsr bss bst btb bte btl bto btr bts btt ebb ebe ebl ebo ebr ebs ebt eeb eee eel eeo eer ees eet elb ele ell elo elr els elt eo- eob eoe eol eoo eor eos eot erb ere erl ero err ers ert es- esb ese esl eso esr ess est etb ete etl eto etr ets ett lbb lbe lbl lbo lbr lbs lbt leb lee lel leo ler les let llb lle lll llo llr lls llt lob loe lol loo lor los lot lrb lro lrr lrs lrt lsb lse lsl lso lsr lss lst ltb lte ltl lto ltr lts ltt ob- obb obe obl obo obr obs obt oeb oee oel oeo oer oes oet olb ole oll olo ols olt oo- oob ool ooo oor oos oot or- orb ore orl oro orr ors ort os- osb ose osl oso osr oss ost ot- otb ote otl oto otr ots ott rbb rbe rbl rbo rbr rbs rbt re- reb ree rel reo rer res ret rle rll rlo rlr rls rlt rob roe rol roo ror ros rot rrb rrl rrr rrs rrt rsb rse rsl rso rsr rss rst rtb rte rtl rto rtr rts rtt sbb sbe sbl sbo sbr sbs sbt se- seb see sel seo ser ses set slb sle sll slo slr sls slt sob soe sol soo sor sos sot sr- srb sre srl sro srr srs srt ss- ssb sse ssl sso ssr sss sst stb ste stl sto str sts stt tbb tbe tbl tbo tbr tbs tbt te- teb tee tel teo ter tes tet tle tll tlo tlr tls tlt to- tob toe tol too tor tos tot trb tre trl tro trr trs trt tsb tse tsl tso tsr tss tst ttb tte ttl tto ttr tts ttt