-er c-- ccc ccd cce ccn cco ccr cdc cdd cde cdn cdo cdr ce- cec ced cee cen ceo cer cn- cnc cnd cne cnn cno cnr co- coc cod coe con coo cor crc crd cre crn cro crr dcc dcd dce dcn dco dcr ddc ddd dde ddn ddo ddr de- dec ded dee den deo der dnc dnd dne dnn dno dnr doc dod doe don doo dor drc drd dre drn dro drr ec- ecc ecd ece ecn eco ecr ed- edc edd ede edn edo edr eec eed eee een eeo eer en- enc end ene enn eno enr eo- eoc eod eoe eon eoo eor erc erd ere ern ero err ncc ncd nce ncn nco ncr ndc ndd nde ndn ndo ndr ne- nec ned nee nen neo ner nnc nne nnn nno no- noc nod noe non noo nor nrc nrd nre nrn nro nrr oc- occ ocd ocn oco ocr odc odd ode odn odo odr oec oed oee oen oeo oer on- onc ond one onn ono onr oo- ooc ood oon ooo oor or- orc ord ore orn oro orr rcc rcd rce rcn rco rcr rdc rdd rde rdn rdo rdr re- rec red ree ren reo rer rnc rnd rnn rno rnr roc rod roe ron roo ror rrc rrd rrn rrr