-er c-- ccc ccd cce ccf cco ccr ccs cct cdc cdd cde cdf cdo cdr cds cdt ce- cec ced cee cef ceo cer ces cet cfc cfd cfe cff cfo cfr cfs cft co- coc cod coe cof coo cor cos cot crc crd cre crf cro crr crs crt csc csd cse csf cso csr css cst ctc ctd cte ctf cto ctr cts ctt dcc dcd dce dcf dco dcr dcs dct ddc ddd dde ddf ddo ddr dds ddt de- dec ded dee def deo der des det dfc dfd dfe dff dfo dfr dfs dft doc dod doe dof doo dor dos dot drc drd dre dro drr drs drt dsc dsd dse dsf dso dsr dss dst dtc dtd dte dtf dto dtr dts dtt ec- ecc ecd ece ecf eco ecr ecs ect ed- edc edd ede edf edo edr eds edt eec eed eee eef eeo eer ees eet ef- efc efd efe eff efo efr efs eft eo- eoc eod eoe eof eoo eor eos eot erc erd ere erf ero err ers ert es- esc esd ese esf eso esr ess est etc etd ete etf eto etr ets ett fcc fcd fce fcf fco fcr fcs fct fdc fdd fde fdf fdo fdr fds fdt fec fed fee fef feo fer fes fet ffc ffd ffe fff ffo ffr ffs fft foc foe fof foo for fos fot frc frd fre frf fro frr frs frt fsc fsd fse fsf fso fsr fss fst ftc ftd fte ftf fto ftr fts ftt oc- occ ocd ocf oco ocr ocs oct odc odd ode odf odo odr ods odt oec oed oee oef oeo oer oes oet of- ofc ofd ofe off ofo ofr ofs oft oo- ooc ood oof ooo oor oos oot or- orc ord ore orf oro orr ors ort os- osc osd ose osf oso osr oss ost ot- otc otd ote otf oto otr ots ott rcc rcd rce rcf rco rcr rcs rct rdc rdd rde rdf rdo rdr rds rdt re- rec red ree ref reo rer res ret rfc rfd rfe rff rfo rfr rfs rft roc rod roe rof roo ror ros rot rrc rrd rrf rrr rrs rrt rsc rsd rse rsf rso rsr rss rst rtc rtd rte rtf rto rtr rts rtt scc scd sce scf sco scr scs sct sdc sdd sde sdf sdo sdr sds sdt se- sec sed see sef seo ser ses set sfc sfd sfe sff sfo sfr sfs sft soc sod soe sof soo sor sos sot sr- src srd sre srf sro srr srs srt ss- ssc ssd sse ssf sso ssr sss sst stc std ste stf sto str sts stt tcc tcd tce tcf tco tcr tcs tct tdc tdd tde tdf tdo tdr tds tdt te- tec ted tee tef teo ter tes tet tfc tfd tfe tff tfo tfr tfs tft to- toc tod toe tof too tor tos tot trc trd tre trf tro trr trs trt tsc tsd tse tsf tso tsr tss tst ttc ttd tte ttf tto ttr tts ttt