c-- ccc ccd ccm cco ccr cdc cdd cdm cdo cdr cmc cmd cmm cmo cmr co- coc cod com coo cor crc crd crm cro crr dcc dcd dcm dco dcr ddc ddd ddm ddo ddr dmc dmd dmm dmo dmr doc dod dom doo dor drc drd drm dro drr m-o m-r mc- mcc mcd mcm mco mcr mdc mdd mdm mdo mdr mmc mmd mmm mmo mmr moc mod mom moo mor mrc mrd mrm mro mrr oc- occ ocd ocm oco ocr odc odd odm odo odr om- omc omd omm omo omr oo- ooc ood oom ooo oor or- orc ord orm oro orr rcc rcd rcm rco rcr rdc rdd rdm rdo rdr rmc rmd rmm rmo rmr roc rod rom roo ror rrc rrd rrm rrr