-er ddd dde ddf ddi ddk ddo ddr dds ddt de- ded dee def dei dek deo der des det dfd dfe dff dfi dfk dfo dfr dfs dft di- did die dif dii dik dio dir dis dit dke dki dkk dko dkr dks dkt dod doe dof doi dok doo dor dos dot drd dre dri drk dro drr drs drt dsd dse dsf dsi dsk dso dsr dss dst dtd dte dtf dti dtk dto dtr dts dtt ed- edd ede edf edi edk edo edr eds edt eed eee eef eek eeo eer ees eet ef- efd efe eff efi efo efr efs eft eid eie eif eii eik eio eir eis eit ekd eke ekf eki eko ekr eks ekt eo- eod eoe eof eoi eok eoo eor eos eot erd ere erf eri erk ero err ers ert es- esd ese esf esi esk eso esr ess est etd ete etf eti etk eto etr ets ett fdd fde fdf fdi fdk fdo fdr fds fdt fed fee fef fei fek feo fer fes fet ffd ffe fff ffi ffk ffo ffr ffs fft fid fie fif fii fik fir fis fit fkf fki fkk fkt foe fof foi fok foo for fos fot frd fre frf fri frk fro frr frs frt fsd fse fsf fsi fsk fso fsr fss fst ftd fte ftf fti ftk fto ftr fts ftt i-d i-f idd ide idf idi idk ido idr ids idt ie- ied iee ief iei iek ier ies iet ifd ife iff ifi ifo ifr ifs ift iid iie iif iii iio iir iis iit ike ikf iki ikk iko ikr iks ikt io- iod ioe iof ioi ioo ior ios iot ir- ird ire irf iri irk iro irr irs irt is- isd ise isf isi isk iso isr iss ist itd ite itf iti itk ito its itt k-t kde kdf kdk kdo kdr kds kdt ke- ked kee kef kei kek keo ker kes ket kfd kff kfi kfo kfs kid kie kif kii kik kio kir kis kit kke kki kkk kkr kks kkt kod koe kof koi kok koo kor kos kot krd krf kri krk kro krr krs krt ksd kse ksf ksi ksk kso ksr kss kst kte ktf ktk kto ktr kts ktt o-i odd ode odf odi odo odr ods odt oed oee oef oei oeo oer oes oet of- ofd ofe off ofi ofo ofr ofs oft oid oie oif oii oik oio oir ois oit okd oke oki okk oko okr oks oo- ood oof ooi ook ooo oor oos oot or- ord ore orf ori ork oro orr ors ort os- osd ose osf osi osk oso osr oss ost ot- otd ote otf oti otk oto otr ots ott rdd rde rdf rdi rdo rdr rds rdt re- red ree ref rei rek reo rer res ret rfd rfe rff rfi rfk rfo rfr rfs rft rid rie rif rii rik rio rir ris rit rke rkf rkk rko rks rkt rod roe rof roi rok roo ror ros rot rrd rrf rri rrk rrr rrs rrt rsd rse rsf rsi rsk rso rsr rss rst rtd rte rtf rti rtk rto rtr rts rtt sdd sde sdf sdi sdk sdo sdr sds sdt se- sed see sef sei sek seo ser ses set sfd sfe sff sfi sfk sfo sfr sfs sft sid sie sif sii sik sio sir sis sit sk- skd ske skf ski skk sko skr sks skt sod soe sof soi sok soo sor sos sot sr- srd sre srf sri srk sro srr srs srt ss- ssd sse ssf ssi ssk sso ssr sss sst std ste stf sti stk sto str sts stt tdd tde tdf tdi tdk tdo tdr tds tdt te- ted tee tef tei tek teo ter tes tet tfd tfe tff tfi tfk tfo tfr tfs tft tid tie tif tii tik tio tir tis tit tke tkk tko tkr tks tkt to- tod toe tof toi tok too tor tos tot trd tre trf tri trk tro trr trs trt tsd tse tsf tsi tsk tso tsr tss tst ttd tte ttf tti ttk tto ttr tts ttt