a-a a-b a-c aaa aab aac aae aaf aam ab- aba abb abc abe abf abm ac- aca acb acc ace acf acm aea aeb aec aee aef aem af- afa afb afc afe aff afm ama amb amc ame amf amm baa bab bac bae baf bam bba bbb bbc bbe bbf bbm bca bcb bcc bce bcf bcm be- bea beb bec bee bef bem bfa bfb bfc bfe bff bfm bma bmb bmc bme bmf bmm c-- caa cab cac cae caf cam cba cbb cbc cbe cbf cbm cca ccb ccc cce ccf ccm ce- cea ceb cec cee cef cem cfa cfb cfc cfe cff cfm cma cmb cmc cme cmf cmm eaa eab eac eae eaf eam eba ebb ebc ebe ebf ebm ec- eca ecb ecc ece ecf ecm eea eeb eec eee eef eem ef- efa efb efc efe eff efm em- ema emb emc eme emf emm faa fab fac fae faf fam fba fbb fbc fbe fbf fbm fca fcb fcc fce fcf fcm fea feb fec fee fef fem ffa ffc ffe fff ffm fma fmb fmc fme fmf fmm m-f maa mab mac mae maf mam mba mbb mbc mbe mbf mbm mc- mca mcb mcc mce mcf mcm mea meb mec mee mef mem mfa mfb mfc mfe mff mfm mma mmb mmc mme mmf mmm