a-a a-c aaa aac aae aam aao aas ac- aca acc ace acm aco acs aea aec aee aem aeo aes ama amc ame amm amo ams aoa aoc aoe aom aoo aos as- asa asc ase asm aso ass c-- caa cac cae cam cao cas cca ccc cce ccm cco ccs ce- cea cec cee cem ceo ces cma cmc cme cmm cmo cms co- coa coc coe com coo cos csa csc cse csm cso css eaa eac eae eam eao eas ec- eca ecc ece ecm eco ecs eea eec eee eem eeo ees em- ema emc eme emm emo ems eo- eoa eoc eoe eom eoo eos es- esa esc ese esm eso ess m-o maa mac mae mam mao mas mc- mca mcc mce mcm mco mcs mea mec mee mem meo mes mma mmc mme mmm mmo mms moa moc moe mom moo mos msa msc mse msm mso mss oaa oac oae oam oao oas oc- oca occ ocm oco ocs oea oec oee oem oeo oes om- oma omc ome omm omo oms oo- ooa ooc oom ooo oos os- osa osc ose osm oso oss saa sac sae sam sao sas sca scc sce scm sco scs se- sea sec see sem seo ses sma smc sme smm smo sms soa soc soe som soo sos ss- ssa ssc sse ssm sso sss