-er c-- ccc ccd cce ccn ccr cdc cdd cde cdn cdr ce- cec ced cee cen cer cn- cnc cnd cne cnn cnr crc crd cre crn crr dcc dcd dce dcn dcr ddc ddd dde ddn ddr de- dec ded dee den der dnc dnd dne dnn dnr drc drd dre drn drr ec- ecc ecd ece ecn ecr ed- edc edd ede edn edr eec eed eee een eer en- enc end ene enn enr erc erd ere ern err ncc ncd nce ncn ncr ndc ndd nde ndn ndr ne- nec ned nee nen ner nnc nne nnn nrc nrd nre nrn nrr rcc rcd rce rcn rcr rdc rdd rde rdn rdr re- rec red ree ren rer rnc rnd rnn rnr rrc rrd rrn rrr