-er c-- ccc ccd cce ccr ccs cct cdc cdd cde cdr cds cdt ce- cec ced cee cer ces cet crc crd cre crr crs crt csc csd cse csr css cst ctc ctd cte ctr cts ctt dcc dcd dce dcr dcs dct ddc ddd dde ddr dds ddt de- dec ded dee der des det drc drd dre drr drs drt dsc dsd dse dsr dss dst dtc dtd dte dtr dts dtt ec- ecc ecd ece ecr ecs ect ed- edc edd ede edr eds edt eec eed eee eer ees eet erc erd ere err ers ert es- esc esd ese esr ess est etc etd ete etr ets ett rcc rcd rce rcr rcs rct rdc rdd rde rdr rds rdt re- rec red ree rer res ret rrc rrd rrr rrs rrt rsc rsd rse rsr rss rst rtc rtd rte rtr rts rtt scc scd sce scr scs sct sdc sdd sde sdr sds sdt se- sec sed see ser ses set sr- src srd sre srr srs srt ss- ssc ssd sse ssr sss sst stc std ste str sts stt tcc tcd tce tcr tcs tct tdc tdd tde tdr tds tdt te- tec ted tee ter tes tet trc trd tre trr trs trt tsc tsd tse tsr tss tst ttc ttd tte ttr tts ttt