a-a a-b a-t aaa aab aag aan aao aat ab- aba abb abg abn abo abt ag- aga agb agg agn ago agt an- ana anb ang ann ano ant aoa aob aog aon aoo aot at- ata atb atg atn ato att baa bab bag ban bao bat bba bbb bbg bbn bbo bbt bga bgb bgg bgn bgo bgt bna bnb bng bnn bno bnt boa bob bog bon boo bot bta btb btg btn bto btt gaa gab gag gan gao gat gba gbg gbn gbo gbt gga ggb ggg ggn ggo ggt gna gnb gnn gno gnt goa gob gog gon goo got gta gtb gtg gtn gto gtt naa nab nag nan nao nat nba nbb nbg nbn nbo nbt nga ngb ngg ngn ngo ngt nna nnb nng nnn nno nnt no- noa nob nog non noo not nta ntb ntg ntn nto ntt oaa oab oag oan oao oat ob- oba obb obg obn obo obt oga ogg ogn ogo ogt on- ona onb ong onn ono ont oo- ooa oob oog oon ooo oot ot- ota otb otg otn oto ott taa tab tag tan tao tat tba tbb tbg tbn tbo tbt tga tgb tgg tgn tgo tgt tna tnb tng tnn tno tnt to- toa tob tog ton too tot tta ttb ttg ttn tto ttt