a-a a-b a-c a-z aaa aab aac aae aav aaz ab- aba abb abc abe abv abz ac- aca acb acc ace acv acz aea aeb aec aee aev aez av- ava avb avc ave avz az- aza azb aze azz baa bab bac bae bav baz bba bbb bbc bbe bca bcb bcc bce bcv bcz be- bea beb bec bee bev bez bva bvb bvc bve bvv bza bze bzz c-- caa cab cac cae cav caz cba cbb cbc cbe cbv cbz cca ccb ccc cce ccv ccz ce- cea ceb cec cee cev cez cva cvb cvc cve cvv cvz cz- czc cze eaa eab eac eae eav eaz eba ebb ebc ebe ebv ec- eca ecb ecc ece ecv eea eeb eec eee eev eva evb evc eve evv eze ezz v-a v-e vaa vab vac vae vav vaz vba vbc vbv vbz vca vcc vce vea veb vec vee vez vva vvb vvc vvv vvz zaa zab zac zav zaz zbb zbc zbv zce zea zeb zec zee zev zez zzz