c-- ccc ccm cco ccs cmc cmm cmo cms cmy co- coc com coo cos coy csc csm cso css csy cyc cym cyo cys m-o mc- mcc mcm mco mcs mmc mmm mmo mms moc mom moo mos moy msc msm mso mss msy my- myc mym myo mys oc- occ ocm oco ocs om- omc omm omo oms omy oo- ooc oom ooo oos os- osc osm oso oss oyo oys scc scm sco scs smc smm smo sms smy soc som soo sos soy ss- ssc ssm sso sss sy- syc sym sys ycc yco ycs ycy ymc ymm ymo yms yoc yom yoo yos yoy ysc ysm yso yss ysy yyc yys yyy