-er ddd dde ddf ddi ddk ddo ddr dds de- ded dee def dei dek deo der des dfd dfe dff dfi dfk dfo dfr dfs di- did die dif dii dik dio dir dis dke dki dkk dko dkr dks dod doe dof doi dok doo dor dos drd dre dri drk dro drr drs dsd dse dsf dsi dsk dso dsr dss ed- edd ede edf edi edk edo edr eds eed eee eef eek eeo eer ees ef- efd efe eff efi efo efr efs eid eie eif eii eik eio eir eis ekd eke ekf eki eko ekr eks eo- eod eoe eof eoi eok eoo eor eos erd ere erf eri erk ero err ers es- esd ese esf esi esk eso esr ess fdd fde fdf fdi fdk fdo fdr fds fed fee fef fei fek feo fer fes ffd ffe fff ffi ffk ffo ffr ffs fid fie fif fii fik fir fis fkf fki fkk foe fof foi fok foo for fos frd fre frf fri frk fro frr frs fsd fse fsf fsi fsk fso fsr fss i-d i-f idd ide idf idi idk ido idr ids ie- ied iee ief iei iek ier ies ifd ife iff ifi ifo ifr ifs iid iie iif iii iio iir iis ike ikf iki ikk iko ikr iks io- iod ioe iof ioi ioo ior ios ir- ird ire irf iri irk iro irr irs is- isd ise isf isi isk iso isr iss kde kdf kdk kdo kdr kds ke- ked kee kef kei kek keo ker kes kfd kff kfi kfo kfs kid kie kif kii kik kio kir kis kke kki kkk kkr kks kod koe kof koi kok koo kor kos krd krf kri krk kro krr krs ksd kse ksf ksi ksk kso ksr kss o-i odd ode odf odi odo odr ods oed oee oef oei oeo oer oes of- ofd ofe off ofi ofo ofr ofs oid oie oif oii oik oio oir ois okd oke oki okk oko okr oks oo- ood oof ooi ook ooo oor oos or- ord ore orf ori ork oro orr ors os- osd ose osf osi osk oso osr oss rdd rde rdf rdi rdo rdr rds re- red ree ref rei rek reo rer res rfd rfe rff rfi rfk rfo rfr rfs rid rie rif rii rik rio rir ris rke rkf rkk rko rks rod roe rof roi rok roo ror ros rrd rrf rri rrk rrr rrs rsd rse rsf rsi rsk rso rsr rss sdd sde sdf sdi sdk sdo sdr sds se- sed see sef sei sek seo ser ses sfd sfe sff sfi sfk sfo sfr sfs sid sie sif sii sik sio sir sis sk- skd ske skf ski skk sko skr sks sod soe sof soi sok soo sor sos sr- srd sre srf sri srk sro srr srs ss- ssd sse ssf ssi ssk sso ssr sss