a-a aaa aaf aam aan aao aax af- afa aff afm afn afo afx ama amf amm amn amo amx an- ana anf anm ann ano anx aoa aof aom aon aoo aox ax- axa axm axn axo axx faa faf fam fan fao fax ffa fff ffm ffn ffo ffx fma fmf fmm fmn fmo fmx fna fnf fnm fnn fnx foa fof fom fon foo fox fxm fxx m-f m-o maa maf mam man mao max mfa mff mfm mfn mfo mma mmf mmm mmn mmo mmx mna mnf mnm mnn mno moa mof mom mon moo mox mxa mxn naa naf nam nan nao nax nfa nff nfn nfo nma nmm nmn nmo nna nnf nnm nnn nno no- noa nof nom non noo nox oaa oaf oam oan oao oax of- ofa off ofm ofn ofo ofx om- oma omf omm omn omo omx on- ona onf onn ono onx oo- ooa oof oom oon ooo oox ox- oxa oxf oxn oxo oxx xaa xaf xam xan xfa xfm xfn xfx xma xmf xmm xmo xmx xna xno xoa xof xom xon xoo xox xxo xxx