-er c-- ccc ccd cce cco ccr ccs ccv cdc cdd cde cdo cdr cds cdv ce- cec ced cee ceo cer ces cev co- coc cod coe coo cor cos cov crc crd cre cro crr crs crv csc csd cse cso csr css csv cvc cvd cve cvo cvr cvs cvv dcc dcd dce dco dcr dcs dcv ddc ddd dde ddo ddr dds de- dec ded dee deo der des dev doc dod doe doo dor dos dov drc drd dre dro drr drs drv dsc dsd dse dso dsr dss dsv dvc dvd dve dvr dvs ec- ecc ecd ece eco ecr ecs ecv ed- edc edd ede edo edr eds eec eed eee eeo eer ees eev eo- eoc eod eoe eoo eor eos erc erd ere ero err ers erv es- esc esd ese eso esr ess esv evc evd eve evo evr evs evv oc- occ ocd oco ocr ocs ocv odc odd ode odo odr ods odv oec oed oee oeo oer oes oo- ooc ood ooo oor oos oov or- orc ord ore oro orr ors orv os- osc osd ose oso osr oss osv ov- ovc ovd ove ovo ovs ovv rcc rcd rce rco rcr rcs rcv rdc rdd rde rdo rdr rds rdv re- rec red ree reo rer res rev roc rod roe roo ror ros rov rrc rrd rrr rrs rsc rsd rse rso rsr rss rsv rvc rvd rve rvo rvr rvs rvv scc scd sce sco scr scs scv sdc sdd sde sdo sdr sds sdv se- sec sed see seo ser ses sev soc sod soe soo sor sos sov sr- src srd sre sro srr srs srv ss- ssc ssd sse sso ssr sss ssv svc svd sve svo svr svs svv v-e vcc vcd vce vco vcr vcs vdc vdd vde vdo vdr vds vdv vec ved vee veo ver ves voc vod voe voo vor vos vov vrc vrd vre vrr vrs vsc vsd vse vso vsr vss vsv vvc vvo vvr vvs vvv