a-a a-b aaa aab aam aan aao aax ab- aba abb abm abn abo abx ama amb amm amn amo amx an- ana anb anm ann ano anx aoa aob aom aon aoo aox ax- axa axm axn axo axx baa bab bam ban bao bax bba bbb bbm bbn bbo bbx bma bmb bmm bmn bmo bmx bna bnb bnn bno bnx boa bob bom bon boo box bxb bxm bxn bxo bxx m-o maa mab mam man mao max mba mbb mbm mbo mbx mma mmb mmm mmn mmo mmx mna mnb mnm mnn mno moa mob mom mon moo mox mxa mxn naa nab nam nan nao nax nba nbb nbm nbn nbo nbx nma nmb nmm nmn nmo nna nnb nnm nnn nno no- noa nob nom non noo nox oaa oab oam oan oao oax ob- oba obb obm obn obo obx om- oma omb omm omn omo omx on- ona onb onn ono onx oo- ooa oob oom oon ooo oox ox- oxa oxb oxn oxo oxx xaa xam xan xbx xma xmm xmo xmx xna xno xoa xom xon xoo xox xxo xxx