c-- ccc ccf ccm cco ccs cfc cff cfm cfo cfs cmc cmf cmm cmo cms co- coc cof com coo cos csc csf csm cso css fcc fcf fcm fco fcs ffc fff ffm ffo ffs fmc fmf fmm fmo fms foc fof fom foo fos fsc fsf fsm fso fss m-f m-o mc- mcc mcf mcm mco mcs mfc mff mfm mfo mfs mmc mmf mmm mmo mms moc mof mom moo mos msc msf msm mso mss oc- occ ocf ocm oco ocs of- ofc off ofm ofo ofs om- omc omf omm omo oms oo- ooc oof oom ooo oos os- osc osf osm oso oss scc scf scm sco scs sfc sff sfm sfo sfs smc smf smm smo sms soc sof som soo sos ss- ssc ssf ssm sso sss