c-- ccc ccd cce ccm ccs cdc cdd cde cdm cds ce- cec ced cee cem ces cmc cmd cme cmm cms csc csd cse csm css dcc dcd dce dcm dcs ddc ddd dde ddm dds de- dec ded dee dem des dmc dmd dme dmm dms dsc dsd dse dsm dss ec- ecc ecd ece ecm ecs ed- edc edd ede edm eds eec eed eee eem ees em- emc emd eme emm ems es- esc esd ese esm ess mc- mcc mcd mce mcm mcs mdc mdd mde mdm mds mec med mee mem mes mmc mmd mme mmm mms msc msd mse msm mss scc scd sce scm scs sdc sdd sde sdm sds se- sec sed see sem ses smc smd sme smm sms ss- ssc ssd sse ssm sss