c-- ccc ccd ccf ccm cco ccr cdc cdd cdf cdm cdo cdr cfc cfd cff cfm cfo cfr cmc cmd cmf cmm cmo cmr co- coc cod cof com coo cor crc crd crf crm cro crr dcc dcd dcf dcm dco dcr ddc ddd ddf ddm ddo ddr dfc dfd dff dfm dfo dfr dmc dmd dmf dmm dmo dmr doc dod dof dom doo dor drc drd drm dro drr fcc fcd fcf fcm fco fcr fdc fdd fdf fdm fdo fdr ffc ffd fff ffm ffo ffr fmc fmd fmf fmm fmo fmr foc fof fom foo for frc frd frf frm fro frr m-f m-o m-r mc- mcc mcd mcf mcm mco mcr mdc mdd mdf mdm mdo mdr mfc mfd mff mfm mfo mfr mmc mmd mmf mmm mmo mmr moc mod mof mom moo mor mrc mrd mrf mrm mro mrr oc- occ ocd ocf ocm oco ocr odc odd odf odm odo odr of- ofc ofd off ofm ofo ofr om- omc omd omf omm omo omr oo- ooc ood oof oom ooo oor or- orc ord orf orm oro orr rcc rcd rcf rcm rco rcr rdc rdd rdf rdm rdo rdr rfc rfd rff rfm rfo rfr rmc rmd rmf rmm rmo rmr roc rod rof rom roo ror rrc rrd rrf rrm rrr