a-a a-b aaa aab aad aak aam aao ab- aba abb abd abk abm abo ad- ada adb add adk adm ado aka akb akd akk akm ako ama amb amd amk amm amo aoa aob aod aok aom aoo baa bab bad bak bam bao bba bbb bbd bbk bbm bbo bda bdb bdd bdk bdm bdo bka bkb bkk bkm bko bma bmb bmd bmk bmm bmo boa bob bod bok bom boo daa dab dad dak dam dao dba dbb dbd dbk dbm dbo dda ddb ddd ddk ddm ddo dka dkb dkk dkm dko dma dmb dmd dmk dmm dmo doa dob dod dok dom doo ka- kaa kab kad kak kam kao kba kbb kbd kbk kbm kbo kda kdb kdk kdm kdo kkb kkk kkm kma kmb kmd kmk kmm kmo koa kob kod kok kom koo m-o maa mab mad mak mam mao mba mbb mbd mbk mbm mbo mda mdb mdd mdk mdm mdo mka mkb mkd mkk mkm mko mma mmb mmd mmk mmm mmo moa mob mod mok mom moo oaa oab oad oak oam oao ob- oba obb obd obk obm obo oda odb odd odm odo oka okb okd okk oko om- oma omb omd omm omo oo- ooa oob ood ook oom ooo