a-a a-c a-z aaa aac aae aam aaz ac- aca acc ace acm acz aea aec aee aem aez ama amc ame amm amz az- aza aze azm azz c-- caa cac cae cam caz cca ccc cce ccm ccz ce- cea cec cee cem cez cma cmc cme cmm cz- czc cze czm eaa eac eae eam eaz ec- eca ecc ece ecm eea eec eee eem em- ema emc eme emm eze ezz maa mac mae mam maz mc- mca mcc mce mcm mcz mea mec mee mem mez mma mmc mme mmm mmz mza mzm zaa zac zam zaz zce zea zec zee zem zez zma zmc zmm zzz