-er c-- ccc ccd cce ccr ccv cdc cdd cde cdr cdv ce- cec ced cee cer cev crc crd cre crr crv cvc cvd cve cvr cvv dcc dcd dce dcr dcv ddc ddd dde ddr de- dec ded dee der dev drc drd dre drr drv dvc dvd dve dvr ec- ecc ecd ece ecr ecv ed- edc edd ede edr eec eed eee eer eev erc erd ere err erv evc evd eve evr evv rcc rcd rce rcr rcv rdc rdd rde rdr rdv re- rec red ree rer rev rrc rrd rrr rvc rvd rve rvr rvv v-e vcc vcd vce vcr vdc vdd vde vdr vdv vec ved vee ver vrc vrd vre vrr vvc vvr vvv