c-- ccc cce cck ccm cco ce- cec cee cek cem ceo ckc ckm cko cmc cme cmk cmm cmo co- coc coe cok com coo ec- ecc ece eck ecm eco eec eee eek eem eeo ekc eke eko em- emc eme emk emm emo eo- eoc eoe eok eom eoo kcc kce kck kcm ke- kec kee kek kem keo kkc kke kkk kkm kmc kme kmk kmm kmo koc koe kok kom koo m-o mc- mcc mce mck mcm mco mec mee mek mem meo mkc mke mkk mkm mko mmc mme mmk mmm mmo moc moe mok mom moo oc- occ ock ocm oco oec oee oem oeo okc oke okk oko om- omc ome omm omo oo- ooc ook oom ooo