-er c-- ccc ccd cce ccr cct cdc cdd cde cdr cdt ce- cec ced cee cer cet crc crd cre crr crt ctc ctd cte ctr ctt dcc dcd dce dcr dct ddc ddd dde ddr ddt de- dec ded dee der det drc drd dre drr drt dtc dtd dte dtr dtt ec- ecc ecd ece ecr ect ed- edc edd ede edr edt eec eed eee eer eet erc erd ere err ert etc etd ete etr ett rcc rcd rce rcr rct rdc rdd rde rdr rdt re- rec red ree rer ret rrc rrd rrr rrt rtc rtd rte rtr rtt tcc tcd tce tcr tct tdc tdd tde tdr tdt te- tec ted tee ter tet trc trd tre trr trt ttc ttd tte ttr ttt