-er c-- ccc ccd cce ccr ccs ccu cdc cdd cde cdr cds cdu ce- cec ced cee cer ces ceu crc crd cre crr crs cru csc csd cse csr css csu cuc cud cue cur cus cuu dcc dcd dce dcr dcs dcu ddc ddd dde ddr dds ddu de- dec ded dee der des deu drc drd dre drr drs dru dsc dsd dse dsr dss dsu duc dud due dur dus ec- ecc ecd ece ecr ecs ecu ed- edc edd ede edr eds edu eec eed eee eer ees erc erd ere err ers eru es- esc esd ese esr ess esu eu- euc eud eue eur eus rcc rcd rce rcr rcs rcu rdc rdd rde rdr rds rdu re- rec red ree rer res reu rrc rrd rrr rrs rru rsc rsd rse rsr rss rsu ruc rud rue rur rus ruu scc scd sce scr scs scu sdc sdd sde sdr sds sdu se- sec sed see ser ses seu sr- src srd sre srr srs ss- ssc ssd sse ssr sss ssu suc sud sue sur sus suu ucc ucd uce ucr ucs ucu udc udd ude udr uds udu uec ued uee uer ues ur- urc urd ure urr urs uru usc usd use usr uss usu uuc uue uur uus uuu