-er c-- ccc cce ccf ccm cco ccr ccs ce- cec cee cef cem ceo cer ces cfc cfe cff cfm cfo cfr cfs cmc cme cmf cmm cmo cmr cms co- coc coe cof com coo cor cos crc cre crf crm cro crr crs csc cse csf csm cso csr css ec- ecc ece ecf ecm eco ecr ecs eec eee eef eem eeo eer ees ef- efc efe eff efm efo efr efs em- emc eme emf emm emo emr ems eo- eoc eoe eof eom eoo eor eos erc ere erf erm ero err ers es- esc ese esf esm eso esr ess fcc fce fcf fcm fco fcr fcs fec fee fef fem feo fer fes ffc ffe fff ffm ffo ffr ffs fmc fme fmf fmm fmo fmr fms foc foe fof fom foo for fos frc fre frf frm fro frr frs fsc fse fsf fsm fso fsr fss m-f m-o m-r mc- mcc mce mcf mcm mco mcr mcs mec mee mef mem meo mer mes mfc mfe mff mfm mfo mfr mfs mmc mme mmf mmm mmo mmr mms moc moe mof mom moo mor mos mrc mre mrf mrm mro mrr mrs msc mse msf msm mso msr mss oc- occ ocf ocm oco ocr ocs oec oee oef oem oeo oer oes of- ofc ofe off ofm ofo ofr ofs om- omc ome omf omm omo omr oms oo- ooc oof oom ooo oor oos or- orc ore orf orm oro orr ors os- osc ose osf osm oso osr oss rcc rce rcf rcm rco rcr rcs re- rec ree ref rem reo rer res rfc rfe rff rfm rfo rfr rfs rmc rme rmf rmm rmo rmr rms roc roe rof rom roo ror ros rrc rrf rrm rrr rrs rsc rse rsf rsm rso rsr rss scc sce scf scm sco scr scs se- sec see sef sem seo ser ses sfc sfe sff sfm sfo sfr sfs smc sme smf smm smo smr sms soc soe sof som soo sor sos sr- src sre srf srm sro srr srs ss- ssc sse ssf ssm sso ssr sss