a-a a-b a-t aaa aab aae aag aao aat ab- aba abb abe abg abo abt aea aeb aee aeg aeo aet ag- aga agb age agg ago agt aoa aob aoe aog aoo aot at- ata atb ate atg ato att baa bab bae bag bao bat bba bbb bbe bbg bbo bbt be- bea beb bee beg beo bet bga bgb bge bgg bgo bgt boa bob boe bog boo bot bta btb bte btg bto btt eaa eab eae eag eao eat eba ebb ebe ebg ebo ebt eea eeb eee eeg eeo eet ega egb ege egg ego egt eo- eoa eob eoe eog eoo eot eta etb ete etg eto ett gaa gab gae gag gao gat gba gbe gbg gbo gbt ge- gea geb gee geg geo get gga ggb ggg ggo ggt goa gob goe gog goo got gta gtb gte gtg gto gtt oaa oab oae oag oao oat ob- oba obb obe obg obo obt oea oeb oee oeg oeo oet oga oge ogg ogo ogt oo- ooa oob oog ooo oot ot- ota otb ote otg oto ott taa tab tae tag tao tat tba tbb tbe tbg tbo tbt te- tea teb tee teg teo tet tga tgb tge tgg tgo tgt to- toa tob toe tog too tot tta ttb tte ttg tto ttt