-er c-- ccc ccd cce ccp ccr cdc cdd cde cdp cdr ce- cec ced cee cep cer cpc cpd cpe cpp cpr crc crd cre crp crr dcc dcd dce dcp dcr ddc ddd dde ddp ddr de- dec ded dee dep der dpc dpd dpe dpp dpr drc drd dre drp drr ec- ecc ecd ece ecr ed- edc edd ede edp edr eec eed eee eep eer ep- epc epd epe epp epr erc erd ere erp err p-p pcc pcd pce pcp pcr pdc pdd pde pdp pdr pec ped pee pep per ppc ppd ppe ppp ppr prc prd pre prp prr rcc rcd rce rcp rcr rdc rdd rde rdp rdr re- rec red ree rep rer rpc rpd rpe rpp rpr rrc rrd rrp rrr