a-a a-b a-c a-t aaa aab aac aae aao aat aav ab- aba abb abc abe abo abt abv ac- aca acb acc ace aco act acv aea aeb aec aee aeo aet aev aoa aob aoc aoe aoo aot aov at- ata atb atc ate ato att atv av- ava avb avc ave avo avt baa bab bac bae bao bat bav bba bbb bbc bbe bbo bbt bca bcb bcc bce bco bct bcv be- bea beb bec bee beo bet bev boa bob boc boe boo bot bov bta btb btc bte bto btt btv bva bvb bvc bve bvo bvt bvv c-- caa cab cac cae cao cat cav cba cbb cbc cbe cbo cbt cbv cca ccb ccc cce cco cct ccv ce- cea ceb cec cee ceo cet cev co- coa cob coc coe coo cot cov cta ctb ctc cte cto ctt ctv cva cvb cvc cve cvo cvt cvv eaa eab eac eae eao eat eav eba ebb ebc ebe ebo ebt ebv ec- eca ecb ecc ece eco ect ecv eea eeb eec eee eeo eet eev eo- eoa eob eoc eoe eoo eot eta etb etc ete eto ett etv eva evb evc eve evo evt evv oaa oab oac oae oao oat oav ob- oba obb obc obe obo obt obv oc- oca ocb occ oco oct ocv oea oeb oec oee oeo oet oo- ooa oob ooc ooo oot oov ot- ota otb otc ote oto ott otv ov- ova ovb ovc ove ovo ovv taa tab tac tae tao tat tav tba tbb tbc tbe tbo tbt tbv tca tcb tcc tce tco tct tcv te- tea teb tec tee teo tet tev to- toa tob toc toe too tot tov tta ttb ttc tte tto ttt ttv tva tvb tvc tve tvo tvt v-a v-e vaa vab vac vae vao vat vav vba vbc vbo vbv vca vcc vce vco vct vea veb vec vee veo vet voa vob voc voe voo vot vov vta vtb vtc vte vto vtt vtv vva vvb vvc vvo vvt vvv