-er c-- ccc ccd cce cco ccr cdc cdd cde cdo cdq cdr ce- cec ced cee ceo ceq cer co- coc cod coe coo coq cor cqc cqd cqo crc crd cre cro crq crr dcc dcd dce dco dcr ddc ddd dde ddo ddq ddr de- dec ded dee deo deq der doc dod doe doo doq dor dqe drc drd dre dro drq drr ec- ecc ecd ece eco ecq ecr ed- edc edd ede edo edr eec eed eee eeo eer eo- eoc eod eoe eoo eoq eor eqe eqq erc erd ere ero erq err oc- occ ocd oco ocr odc odd ode odo odr oec oed oee oeo oer oo- ooc ood ooo oor oqo or- orc ord ore oro orr qcc qcd qco qdr qec qed qee qeo qoo qor qqq qrc qre rcc rcd rce rco rcr rdc rdd rde rdo rdr re- rec red ree reo req rer roc rod roe roo ror rqc rrc rrd rrq rrr