c-- ccc cce ccm cco ccp ccs ce- cec cee cem ceo cep ces cmc cme cmm cmo cmp cms co- coc coe com coo cop cos cpc cpe cpm cpo cpp cps csc cse csm cso csp css ec- ecc ece ecm eco ecs eec eee eem eeo eep ees em- emc eme emm emo emp ems eo- eoc eoe eom eoo eop eos ep- epc epe epm epo epp eps es- esc ese esm eso esp ess m-o mc- mcc mce mcm mco mcp mcs mec mee mem meo mep mes mmc mme mmm mmo mmp mms moc moe mom moo mop mos mpc mpe mpm mpo mpp mps msc mse msm mso msp mss oc- occ ocm oco ocp ocs oec oee oem oeo oep oes om- omc ome omm omo omp oms oo- ooc oom ooo oop oos op- opc ope opm opo opp ops os- osc ose osm oso osp oss p-p pcc pce pcm pco pcp pcs pec pee pem peo pep pes pmc pme pmm pmo pmp pms poc poe pom poo pop pos ppc ppe ppm ppo ppp pps ps- psc pse psm pso psp pss scc sce scm sco scp scs se- sec see sem seo sep ses smc sme smm smo smp sms soc soe som soo sop sos spc spe spm spo spp sps ss- ssc sse ssm sso ssp sss