a-a a-c a-z aaa aac aae aav aaz ac- aca acc ace acv acz aea aec aee aev aez av- ava avc ave avz az- aza aze azz c-- caa cac cae cav caz cca ccc cce ccv ccz ce- cea cec cee cev cez cva cvc cve cvv cvz cz- czc cze eaa eac eae eav eaz ec- eca ecc ece ecv eea eec eee eev eva evc eve evv eze ezz v-a v-e vaa vac vae vav vaz vca vcc vce vea vec vee vez vva vvc vvv vvz zaa zac zav zaz zce zea zec zee zev zez zzz