-er c-- ccc ccd cce ccr ccs cct ccu cdc cdd cde cdr cds cdt cdu ce- cec ced cee cer ces cet ceu crc crd cre crr crs crt cru csc csd cse csr css cst csu ctc ctd cte ctr cts ctt ctu cuc cud cue cur cus cut cuu dcc dcd dce dcr dcs dct dcu ddc ddd dde ddr dds ddt ddu de- dec ded dee der des det deu drc drd dre drr drs drt dru dsc dsd dse dsr dss dst dsu dtc dtd dte dtr dts dtt dtu duc dud due dur dus dut ec- ecc ecd ece ecr ecs ect ecu ed- edc edd ede edr eds edt edu eec eed eee eer ees eet erc erd ere err ers ert eru es- esc esd ese esr ess est esu etc etd ete etr ets ett etu eu- euc eud eue eur eus eut rcc rcd rce rcr rcs rct rcu rdc rdd rde rdr rds rdt rdu re- rec red ree rer res ret reu rrc rrd rrr rrs rrt rru rsc rsd rse rsr rss rst rsu rtc rtd rte rtr rts rtt rtu ruc rud rue rur rus rut ruu scc scd sce scr scs sct scu sdc sdd sde sdr sds sdt sdu se- sec sed see ser ses set seu sr- src srd sre srr srs srt ss- ssc ssd sse ssr sss sst ssu stc std ste str sts stt stu suc sud sue sur sus sut suu tcc tcd tce tcr tcs tct tcu tdc tdd tde tdr tds tdt tdu te- tec ted tee ter tes tet teu trc trd tre trr trs trt tru tsc tsd tse tsr tss tst tsu ttc ttd tte ttr tts ttt ttu tuc tud tue tur tus tut tuu ucc ucd uce ucr ucs uct ucu udc udd ude udr uds udt udu uec ued uee uer ues uet ur- urc urd ure urr urs urt uru usc usd use usr uss ust usu utc utd ute utr uts utt utu uuc uue uur uus uut uuu