a-a a-b a-c aaa aab aac aae aao aav ab- aba abb abc abe abo abv ac- aca acb acc ace aco acv aea aeb aec aee aeo aev aoa aob aoc aoe aoo aov av- ava avb avc ave avo baa bab bac bae bao bav bba bbb bbc bbe bbo bca bcb bcc bce bco bcv be- bea beb bec bee beo bev boa bob boc boe boo bov bva bvb bvc bve bvo bvv c-- caa cab cac cae cao cav cba cbb cbc cbe cbo cbv cca ccb ccc cce cco ccv ce- cea ceb cec cee ceo cev co- coa cob coc coe coo cov cva cvb cvc cve cvo cvv eaa eab eac eae eao eav eba ebb ebc ebe ebo ebv ec- eca ecb ecc ece eco ecv eea eeb eec eee eeo eev eo- eoa eob eoc eoe eoo eva evb evc eve evo evv oaa oab oac oae oao oav ob- oba obb obc obe obo obv oc- oca ocb occ oco ocv oea oeb oec oee oeo oo- ooa oob ooc ooo oov ov- ova ovb ovc ove ovo ovv v-a v-e vaa vab vac vae vao vav vba vbc vbo vbv vca vcc vce vco vea veb vec vee veo voa vob voc voe voo vov vva vvb vvc vvo vvv