a-a a-b aaa aab aad aam aao ab- aba abb abd abm abo ad- ada adb add adm ado ama amb amd amm amo aoa aob aod aom aoo baa bab bad bam bao bba bbb bbd bbm bbo bda bdb bdd bdm bdo bma bmb bmd bmm bmo boa bob bod bom boo daa dab dad dam dao dba dbb dbd dbm dbo dda ddb ddd ddm ddo dma dmb dmd dmm dmo doa dob dod dom doo m-o maa mab mad mam mao mba mbb mbd mbm mbo mda mdb mdd mdm mdo mma mmb mmd mmm mmo moa mob mod mom moo oaa oab oad oam oao ob- oba obb obd obm obo oda odb odd odm odo om- oma omb omd omm omo oo- ooa oob ood oom ooo