a-a a-b a-c a-t aaa aab aac aae aag aao aat ab- aba abb abc abe abg abo abt ac- aca acb acc ace acg aco act aea aeb aec aee aeg aeo aet ag- aga agb agc age agg ago agt aoa aob aoc aoe aog aoo aot at- ata atb atc ate atg ato att baa bab bac bae bag bao bat bba bbb bbc bbe bbg bbo bbt bca bcb bcc bce bcg bco bct be- bea beb bec bee beg beo bet bga bgb bgc bge bgg bgo bgt boa bob boc boe bog boo bot bta btb btc bte btg bto btt c-- caa cab cac cae cag cao cat cba cbb cbc cbe cbg cbo cbt cca ccb ccc cce ccg cco cct ce- cea ceb cec cee ceg ceo cet cga cgb cgc cge cgg cgo cgt co- coa cob coc coe cog coo cot cta ctb ctc cte ctg cto ctt eaa eab eac eae eag eao eat eba ebb ebc ebe ebg ebo ebt ec- eca ecb ecc ece ecg eco ect eea eeb eec eee eeg eeo eet ega egb egc ege egg ego egt eo- eoa eob eoc eoe eog eoo eot eta etb etc ete etg eto ett gaa gab gac gae gag gao gat gba gbc gbe gbg gbo gbt gca gcb gcc gce gcg gco gct ge- gea geb gec gee geg geo get gga ggb ggc ggg ggo ggt goa gob goc goe gog goo got gta gtb gtc gte gtg gto gtt oaa oab oac oae oag oao oat ob- oba obb obc obe obg obo obt oc- oca ocb occ ocg oco oct oea oeb oec oee oeg oeo oet oga ogc oge ogg ogo ogt oo- ooa oob ooc oog ooo oot ot- ota otb otc ote otg oto ott taa tab tac tae tag tao tat tba tbb tbc tbe tbg tbo tbt tca tcb tcc tce tcg tco tct te- tea teb tec tee teg teo tet tga tgb tgc tge tgg tgo tgt to- toa tob toc toe tog too tot tta ttb ttc tte ttg tto ttt