a-a a-c aaa aac aam aao aas ac- aca acc acm aco acs ama amc amm amo ams aoa aoc aom aoo aos as- asa asc asm aso ass c-- caa cac cam cao cas cca ccc ccm cco ccs cma cmc cmm cmo cms co- coa coc com coo cos csa csc csm cso css m-o maa mac mam mao mas mc- mca mcc mcm mco mcs mma mmc mmm mmo mms moa moc mom moo mos msa msc msm mso mss oaa oac oam oao oas oc- oca occ ocm oco ocs om- oma omc omm omo oms oo- ooa ooc oom ooo oos os- osa osc osm oso oss saa sac sam sao sas sca scc scm sco scs sma smc smm smo sms soa soc som soo sos ss- ssa ssc ssm sso sss