-er c-- ccc ccd cce cck cco ccr ccs cct cdc cdd cde cdk cdo cdr cds cdt ce- cec ced cee cek ceo cer ces cet ckc ckd cko cks ckt co- coc cod coe cok coo cor cos cot crc crd cre crk cro crr crs crt csc csd cse csk cso csr css cst ctc ctd cte ctk cto ctr cts ctt dcc dcd dce dck dco dcr dcs dct ddc ddd dde ddk ddo ddr dds ddt de- dec ded dee dek deo der des det dkc dke dkk dko dkr dks dkt doc dod doe dok doo dor dos dot drc drd dre drk dro drr drs drt dsc dsd dse dsk dso dsr dss dst dtc dtd dte dtk dto dtr dts dtt ec- ecc ecd ece eck eco ecr ecs ect ed- edc edd ede edk edo edr eds edt eec eed eee eek eeo eer ees eet ekc ekd eke eko ekr eks ekt eo- eoc eod eoe eok eoo eor eos eot erc erd ere erk ero err ers ert es- esc esd ese esk eso esr ess est etc etd ete etk eto etr ets ett k-t kcc kcd kce kck kcr kcs kct kdc kde kdk kdo kdr kds kdt ke- kec ked kee kek keo ker kes ket kkc kke kkk kkr kks kkt koc kod koe kok koo kor kos kot krc krd krk kro krr krs krt ksc ksd kse ksk kso ksr kss kst ktc kte ktk kto ktr kts ktt oc- occ ocd ock oco ocr ocs oct odc odd ode odo odr ods odt oec oed oee oeo oer oes oet okc okd oke okk oko okr oks oo- ooc ood ook ooo oor oos oot or- orc ord ore ork oro orr ors ort os- osc osd ose osk oso osr oss ost ot- otc otd ote otk oto otr ots ott rcc rcd rce rco rcr rcs rct rdc rdd rde rdo rdr rds rdt re- rec red ree rek reo rer res ret rkc rke rkk rko rks rkt roc rod roe rok roo ror ros rot rrc rrd rrk rrr rrs rrt rsc rsd rse rsk rso rsr rss rst rtc rtd rte rtk rto rtr rts rtt scc scd sce sck sco scr scs sct sdc sdd sde sdk sdo sdr sds sdt se- sec sed see sek seo ser ses set sk- skc skd ske skk sko skr sks skt soc sod soe sok soo sor sos sot sr- src srd sre srk sro srr srs srt ss- ssc ssd sse ssk sso ssr sss sst stc std ste stk sto str sts stt tcc tcd tce tck tco tcr tcs tct tdc tdd tde tdk tdo tdr tds tdt te- tec ted tee tek teo ter tes tet tkc tke tkk tko tkr tks tkt to- toc tod toe tok too tor tos tot trc trd tre trk tro trr trs trt tsc tsd tse tsk tso tsr tss tst ttc ttd tte ttk tto ttr tts ttt