c-- ccc cce cck ccm cco ccs ce- cec cee cek cem ceo ces ckc ckm cko cks cmc cme cmk cmm cmo cms co- coc coe cok com coo cos csc cse csk csm cso css ec- ecc ece eck ecm eco ecs eec eee eek eem eeo ees ekc eke eko eks em- emc eme emk emm emo ems eo- eoc eoe eok eom eoo eos es- esc ese esk esm eso ess kcc kce kck kcm kcs ke- kec kee kek kem keo kes kkc kke kkk kkm kks kmc kme kmk kmm kmo kms koc koe kok kom koo kos ksc kse ksk ksm kso kss m-o mc- mcc mce mck mcm mco mcs mec mee mek mem meo mes mkc mke mkk mkm mko mks mmc mme mmk mmm mmo mms moc moe mok mom moo mos msc mse msk msm mso mss oc- occ ock ocm oco ocs oec oee oem oeo oes okc oke okk oko oks om- omc ome omm omo oms oo- ooc ook oom ooo oos os- osc ose osk osm oso oss scc sce sck scm sco scs se- sec see sek sem seo ses sk- skc ske skk skm sko sks smc sme smk smm smo sms soc soe sok som soo sos ss- ssc sse ssk ssm sso sss