a-a a-b aaa aab aad aae aam ab- aba abb abd abe abm ad- ada adb add ade adm aea aeb aed aee aem ama amb amd ame amm baa bab bad bae bam bba bbb bbd bbe bbm bda bdb bdd bde bdm be- bea beb bed bee bem bma bmb bmd bme bmm daa dab dad dae dam dba dbb dbd dbe dbm dda ddb ddd dde ddm de- dea deb ded dee dem dma dmb dmd dme dmm eaa eab ead eae eam eba ebb ebd ebe ebm ed- eda edb edd ede edm eea eeb eed eee eem em- ema emb emd eme emm maa mab mad mae mam mba mbb mbd mbe mbm mda mdb mdd mde mdm mea meb med mee mem mma mmb mmd mme mmm