a-a a-b aaa aab aad aae aaf aam aan ab- aba abb abd abe abf abm abn ad- ada adb add ade adf adm adn aea aeb aed aee aef aem aen af- afa afb afd afe aff afm afn ama amb amd ame amf amm amn an- ana anb and ane anf anm ann baa bab bad bae baf bam ban bba bbb bbd bbe bbf bbm bbn bda bdb bdd bde bdf bdm be- bea beb bed bee bef bem ben bfa bfb bfd bfe bff bfm bfn bma bmb bmd bme bmf bmm bmn bna bnb bnd bne bnf bnn daa dab dad dae daf dam dan dba dbb dbd dbe dbf dbm dbn dda ddb ddd dde ddf ddm ddn de- dea deb ded dee def dem den dfa dfb dfd dfe dff dfm dfn dma dmb dmd dme dmf dmm dmn dna dnb dnd dne dnf dnm dnn eaa eab ead eae eaf eam ean eba ebb ebd ebe ebf ebm ebn ed- eda edb edd ede edf edm edn eea eeb eed eee eef eem een ef- efa efb efd efe eff efm em- ema emb emd eme emf emm emn en- ena enb end ene enf enm enn faa fab fad fae faf fam fan fba fbb fbd fbe fbf fbm fbn fda fdb fdd fde fdf fdm fdn fea feb fed fee fef fem fen ffa ffd ffe fff ffm ffn fma fmb fmd fme fmf fmm fmn fna fnb fnd fne fnf fnm fnn m-f maa mab mad mae maf mam man mba mbb mbd mbe mbf mbm mda mdb mdd mde mdf mdm mdn mea meb med mee mef mem men mfa mfb mfd mfe mff mfm mfn mma mmb mmd mme mmf mmm mmn mna mnb mne mnf mnm mnn naa nab nad nae naf nam nan nba nbb nbd nbe nbf nbm nbn nda ndb ndd nde ndf ndm ndn ne- nea neb ned nee nef nem nen nfa nfb nfd nfe nff nfn nma nmb nmd nme nmm nmn nna nnb nne nnf nnm nnn