a-a a-b aaa aab aad aae aam aan ab- aba abb abd abe abm abn ad- ada adb add ade adm adn aea aeb aed aee aem aen ama amb amd ame amm amn an- ana anb and ane anm ann baa bab bad bae bam ban bba bbb bbd bbe bbm bbn bda bdb bdd bde bdm be- bea beb bed bee bem ben bma bmb bmd bme bmm bmn bna bnb bnd bne bnn daa dab dad dae dam dan dba dbb dbd dbe dbm dbn dda ddb ddd dde ddm ddn de- dea deb ded dee dem den dma dmb dmd dme dmm dmn dna dnb dnd dne dnm dnn eaa eab ead eae eam ean eba ebb ebd ebe ebm ebn ed- eda edb edd ede edm edn eea eeb eed eee eem een em- ema emb emd eme emm emn en- ena enb end ene enm enn maa mab mad mae mam man mba mbb mbd mbe mbm mda mdb mdd mde mdm mdn mea meb med mee mem men mma mmb mmd mme mmm mmn mna mnb mne mnm mnn naa nab nad nae nam nan nba nbb nbd nbe nbm nbn nda ndb ndd nde ndm ndn ne- nea neb ned nee nem nen nma nmb nmd nme nmm nmn nna nnb nne nnm nnn