a-a a-b a-i a-t aaa aab aaf aag aai aao aat ab- aba abb abf abg abi abo abt af- afa afb aff afg afi afo aft ag- aga agb agf agg agi ago agt ai- aia aib aif aig aii aio ait aoa aob aof aog aoi aoo aot at- ata atb atf atg ati ato att baa bab baf bag bai bao bat bba bbb bbf bbg bbi bbo bbt bfa bfb bff bfg bfi bfo bft bga bgb bgf bgg bgi bgo bgt bi- bia bib bif big bii bio bit boa bob bof bog boi boo bot bta btb btf btg bti bto btt faa fab faf fag fai fao fat fba fbb fbf fbg fbi fbo fbt ffa fff ffg ffi ffo fft fga fgb fgf fgg fgi fgt fia fib fif fig fii fit foa fob fof fog foi foo fot fta ftb ftf ftg fti fto ftt gaa gab gaf gag gai gao gat gba gbf gbg gbi gbo gbt gfa gfb gff gfi gfo gft gga ggb ggg ggi ggo ggt gia gib gif gig gii gio git goa gob gof gog goi goo got gta gtb gtf gtg gti gto gtt i-f ia- iaa iab iaf iag iai iao iat iba ibb ibf ibg ibi ibo ibt ifa ifb iff ifg ifi ifo ift iga igb igf igg igi igo igt iia iib iif iii iio iit io- ioa iob iof iog ioi ioo iot ita itb itf itg iti ito itt o-i oaa oab oaf oag oai oao oat ob- oba obb obf obg obi obo obt of- ofa ofb off ofg ofi ofo oft oga ogf ogg ogi ogo ogt oia oib oif oii oio oit oo- ooa oob oof oog ooi ooo oot ot- ota otb otf otg oti oto ott taa tab taf tag tai tao tat tba tbb tbf tbg tbi tbo tbt tfa tfb tff tfg tfi tfo tft tga tgb tgf tgg tgi tgo tgt tia tib tif tig tii tio tit to- toa tob tof tog toi too tot tta ttb ttf ttg tti tto ttt