-er c-- ccc cce ccm cco ccp ccr ccs ce- cec cee cem ceo cep cer ces cmc cme cmm cmo cmp cmr cms co- coc coe com coo cop cor cos cpc cpe cpm cpo cpp cpr cps crc cre crm cro crp crr crs csc cse csm cso csp csr css ec- ecc ece ecm eco ecr ecs eec eee eem eeo eep eer ees em- emc eme emm emo emp emr ems eo- eoc eoe eom eoo eop eor eos ep- epc epe epm epo epp epr eps erc ere erm ero erp err ers es- esc ese esm eso esp esr ess m-o m-r mc- mcc mce mcm mco mcp mcr mcs mec mee mem meo mep mer mes mmc mme mmm mmo mmp mmr mms moc moe mom moo mop mor mos mpc mpe mpm mpo mpp mpr mps mrc mre mrm mro mrp mrr mrs msc mse msm mso msp msr mss oc- occ ocm oco ocp ocr ocs oec oee oem oeo oep oer oes om- omc ome omm omo omp omr oms oo- ooc oom ooo oop oor oos op- opc ope opm opo opp opr ops or- orc ore orm oro orp orr ors os- osc ose osm oso osp osr oss p-p pcc pce pcm pco pcp pcr pcs pec pee pem peo pep per pes pmc pme pmm pmo pmp pmr pms poc poe pom poo pop por pos ppc ppe ppm ppo ppp ppr pps prc pre prm pro prp prr prs ps- psc pse psm pso psp psr pss rcc rce rcm rco rcp rcr rcs re- rec ree rem reo rep rer res rmc rme rmm rmo rmp rmr rms roc roe rom roo rop ror ros rpc rpe rpm rpo rpp rpr rps rrc rrm rrp rrr rrs rsc rse rsm rso rsp rsr rss scc sce scm sco scp scr scs se- sec see sem seo sep ser ses smc sme smm smo smp smr sms soc soe som soo sop sor sos spc spe spm spo spp spr sps sr- src sre srm sro srp srr srs ss- ssc sse ssm sso ssp ssr sss