-er c-- ccc ccd cce ccf cck cco ccr cct cdc cdd cde cdf cdk cdo cdr cdt ce- cec ced cee cef cek ceo cer cet cfc cfd cfe cff cfk cfo cfr cft ckc ckd cko ckt co- coc cod coe cof cok coo cor cot crc crd cre crf crk cro crr crt ctc ctd cte ctf ctk cto ctr ctt dcc dcd dce dcf dck dco dcr dct ddc ddd dde ddf ddk ddo ddr ddt de- dec ded dee def dek deo der det dfc dfd dfe dff dfk dfo dfr dft dkc dke dkk dko dkr dkt doc dod doe dof dok doo dor dot drc drd dre drk dro drr drt dtc dtd dte dtf dtk dto dtr dtt ec- ecc ecd ece ecf eck eco ecr ect ed- edc edd ede edf edk edo edr edt eec eed eee eef eek eeo eer eet ef- efc efd efe eff efo efr eft ekc ekd eke ekf eko ekr ekt eo- eoc eod eoe eof eok eoo eor eot erc erd ere erf erk ero err ert etc etd ete etf etk eto etr ett fcc fcd fce fcf fck fco fcr fct fdc fdd fde fdf fdk fdo fdr fdt fec fed fee fef fek feo fer fet ffc ffd ffe fff ffk ffo ffr fft fkc fkf fkk fkt foc foe fof fok foo for fot frc frd fre frf frk fro frr frt ftc ftd fte ftf ftk fto ftr ftt k-t kcc kcd kce kck kcr kct kdc kde kdf kdk kdo kdr kdt ke- kec ked kee kef kek keo ker ket kfc kfd kff kfo kkc kke kkk kkr kkt koc kod koe kof kok koo kor kot krc krd krf krk kro krr krt ktc kte ktf ktk kto ktr ktt oc- occ ocd ocf ock oco ocr oct odc odd ode odf odo odr odt oec oed oee oef oeo oer oet of- ofc ofd ofe off ofo ofr oft okc okd oke okk oko okr oo- ooc ood oof ook ooo oor oot or- orc ord ore orf ork oro orr ort ot- otc otd ote otf otk oto otr ott rcc rcd rce rcf rco rcr rct rdc rdd rde rdf rdo rdr rdt re- rec red ree ref rek reo rer ret rfc rfd rfe rff rfk rfo rfr rft rkc rke rkf rkk rko rkt roc rod roe rof rok roo ror rot rrc rrd rrf rrk rrr rrt rtc rtd rte rtf rtk rto rtr rtt tcc tcd tce tcf tck tco tcr tct tdc tdd tde tdf tdk tdo tdr tdt te- tec ted tee tef tek teo ter tet tfc tfd tfe tff tfk tfo tfr tft tkc tke tkk tko tkr tkt to- toc tod toe tof tok too tor tot trc trd tre trf trk tro trr trt ttc ttd tte ttf ttk tto ttr ttt