-er c-- ccc ccd cce cco ccr ccs cdc cdd cde cdo cdq cdr cds ce- cec ced cee ceo ceq cer ces co- coc cod coe coo coq cor cos cqc cqd cqo cqs crc crd cre cro crq crr crs csc csd cse cso csq csr css dcc dcd dce dco dcr dcs ddc ddd dde ddo ddq ddr dds de- dec ded dee deo deq der des doc dod doe doo doq dor dos dqe dqs drc drd dre dro drq drr drs dsc dsd dse dso dsq dsr dss ec- ecc ecd ece eco ecq ecr ecs ed- edc edd ede edo edr eds eec eed eee eeo eer ees eo- eoc eod eoe eoo eoq eor eos eqe eqq eqs erc erd ere ero erq err ers es- esc esd ese eso esq esr ess oc- occ ocd oco ocr ocs odc odd ode odo odr ods oec oed oee oeo oer oes oo- ooc ood ooo oor oos oqo or- orc ord ore oro orr ors os- osc osd ose oso osq osr oss qcc qcd qco qcs qdr qds qec qed qee qeo qoo qor qos qqq qrc qre qrs qsc qsd qso qsr rcc rcd rce rco rcr rcs rdc rdd rde rdo rdr rds re- rec red ree reo req rer res roc rod roe roo ror ros rqc rqs rrc rrd rrq rrr rrs rsc rsd rse rso rsq rsr rss scc scd sce sco scr scs sdc sdd sde sdo sdq sdr sds se- sec sed see seo seq ser ses soc sod soe soo soq sor sos sqd sqq sqr sqs sr- src srd sre sro srq srr srs ss- ssc ssd sse sso ssq ssr sss