a-a a-b aaa aab aak aam aao aax ab- aba abb abk abm abo abx aka akb akk akm ako ama amb amk amm amo amx aoa aob aok aom aoo aox ax- axa axk axm axo axx baa bab bak bam bao bax bba bbb bbk bbm bbo bbx bka bkb bkk bkm bko bkx bma bmb bmk bmm bmo bmx boa bob bok bom boo box bxb bxm bxo bxx ka- kaa kab kak kam kao kax kba kbb kbk kbm kbo kbx kkb kkk kkm kma kmb kmk kmm kmo koa kob kok kom koo kxm kxo m-o maa mab mak mam mao max mba mbb mbk mbm mbo mbx mka mkb mkk mkm mko mkx mma mmb mmk mmm mmo mmx moa mob mok mom moo mox mxa oaa oab oak oam oao oax ob- oba obb obk obm obo obx oka okb okk oko om- oma omb omm omo omx oo- ooa oob ook oom ooo oox ox- oxa oxb oxo oxx xaa xak xam xbx xkb xma xmk xmm xmo xmx xoa xok xom xoo xox xxo xxx