-er c-- ccc ccd cce ccp ccr ccs cdc cdd cde cdp cdr cds ce- cec ced cee cep cer ces cpc cpd cpe cpp cpr cps crc crd cre crp crr crs csc csd cse csp csr css dcc dcd dce dcp dcr dcs ddc ddd dde ddp ddr dds de- dec ded dee dep der des dpc dpd dpe dpp dpr dps drc drd dre drp drr drs dsc dsd dse dsp dsr dss ec- ecc ecd ece ecr ecs ed- edc edd ede edp edr eds eec eed eee eep eer ees ep- epc epd epe epp epr eps erc erd ere erp err ers es- esc esd ese esp esr ess p-p pcc pcd pce pcp pcr pcs pdc pdd pde pdp pdr pds pec ped pee pep per pes ppc ppd ppe ppp ppr pps prc prd pre prp prr prs ps- psc psd pse psp psr pss rcc rcd rce rcp rcr rcs rdc rdd rde rdp rdr rds re- rec red ree rep rer res rpc rpd rpe rpp rpr rps rrc rrd rrp rrr rrs rsc rsd rse rsp rsr rss scc scd sce scp scr scs sdc sdd sde sdp sdr sds se- sec sed see sep ser ses spc spd spe spp spr sps sr- src srd sre srp srr srs ss- ssc ssd sse ssp ssr sss