-er -ol bbb bbd bbe bbk bbl bbo bbr bbs bbt bdb bdd bde bdk bdl bdo bdr bds bdt be- beb bed bee bek bel beo ber bes bet bkb bke bkk bkl bko bkr bks bkt blb bld ble blk bll blo blr bls blt bob bod boe bok bol boo bor bos bot brb brd bre brk brl bro brr brs brt bsb bsd bse bsk bsl bso bsr bss bst btb btd bte btk btl bto btr bts btt dbb dbd dbe dbk dbl dbo dbr dbs dbt ddb ddd dde ddk ddl ddo ddr dds ddt de- deb ded dee dek del deo der des det dkb dke dkk dkl dko dkr dks dkt dl- dlb dld dle dlk dll dlo dlr dls dlt dob dod doe dok dol doo dor dos dot drb drd dre drk drl dro drr drs drt dsb dsd dse dsk dsl dso dsr dss dst dtb dtd dte dtk dtl dto dtr dts dtt ebb ebd ebe ebk ebl ebo ebr ebs ebt ed- edb edd ede edk edl edo edr eds edt eeb eed eee eek eel eeo eer ees eet ekb ekd eke ekl eko ekr eks ekt elb eld ele elk ell elo elr els elt eo- eob eod eoe eok eol eoo eor eos eot erb erd ere erk erl ero err ers ert es- esb esd ese esk esl eso esr ess est etb etd ete etk etl eto etr ets ett k-t kbb kbd kbe kbk kbl kbo kbr kbs kdb kde kdk kdl kdo kdr kds kdt ke- keb ked kee kek kel keo ker kes ket kkb kke kkk kkl kkr kks kkt kl- klb kld klo klr kls klt kob kod koe kok kol koo kor kos kot krd krk krl kro krr krs krt ksb ksd kse ksk ksl kso ksr kss kst ktb kte ktk ktl kto ktr kts ktt lbb lbd lbe lbk lbl lbo lbr lbs lbt ldb ldd lde ldk ldl ldo ldr lds ldt leb led lee lek lel leo ler les let lkb lkl lkr lks lkt llb lld lle llk lll llo llr lls llt lob lod loe lok lol loo lor los lot lrb lrd lrk lro lrr lrs lrt lsb lsd lse lsk lsl lso lsr lss lst ltb ltd lte ltk ltl lto ltr lts ltt ob- obb obd obe obk obl obo obr obs obt odb odd ode odl odo odr ods odt oeb oed oee oel oeo oer oes oet okb okd oke okk okl oko okr oks olb old ole olk oll olo ols olt oo- oob ood ook ool ooo oor oos oot or- orb ord ore ork orl oro orr ors ort os- osb osd ose osk osl oso osr oss ost ot- otb otd ote otk otl oto otr ots ott rbb rbd rbe rbk rbl rbo rbr rbs rbt rdb rdd rde rdl rdo rdr rds rdt re- reb red ree rek rel reo rer res ret rkb rke rkk rko rks rkt rld rle rll rlo rlr rls rlt rob rod roe rok rol roo ror ros rot rrb rrd rrk rrl rrr rrs rrt rsb rsd rse rsk rsl rso rsr rss rst rtb rtd rte rtk rtl rto rtr rts rtt sbb sbd sbe sbk sbl sbo sbr sbs sbt sdb sdd sde sdk sdl sdo sdr sds sdt se- seb sed see sek sel seo ser ses set sk- skb skd ske skk skl sko skr sks skt slb sld sle slk sll slo slr sls slt sob sod soe sok sol soo sor sos sot sr- srb srd sre srk srl sro srr srs srt ss- ssb ssd sse ssk ssl sso ssr sss sst stb std ste stk stl sto str sts stt tbb tbd tbe tbk tbl tbo tbr tbs tbt tdb tdd tde tdk tdl tdo tdr tds tdt te- teb ted tee tek tel teo ter tes tet tkb tke tkk tkl tko tkr tks tkt tld tle tlk tll tlo tlr tls tlt to- tob tod toe tok tol too tor tos tot trb trd tre trk trl tro trr trs trt tsb tsd tse tsk tsl tso tsr tss tst ttb ttd tte ttk ttl tto ttr tts ttt