a-a a-b a-t aaa aab aag aao aat aau ab- aba abb abg abo abt abu ag- aga agb agg ago agt agu aoa aob aog aoo aot aou at- ata atb atg ato att atu au- aua aub aug auo aut b-u baa bab bag bao bat bau bba bbb bbg bbo bbt bbu bga bgb bgg bgo bgt bgu boa bob bog boo bot bou bta btb btg bto btt btu bua bub bug buo but buu gaa gab gag gao gat gau gba gbg gbo gbt gbu gga ggb ggg ggo ggt ggu goa gob gog goo got gou gta gtb gtg gto gtt gtu gu- gua gub gug guo gut guu oaa oab oag oao oat oau ob- oba obb obg obo obt obu oga ogg ogo ogt oo- ooa oob oog ooo oot ot- ota otb otg oto ott otu ou- oua ouo out taa tab tag tao tat tau tba tbb tbg tbo tbt tbu tga tgb tgg tgo tgt tgu to- toa tob tog too tot tou tta ttb ttg tto ttt ttu tua tub tug tuo tut tuu ua- uaa uab uag uao uat uau uba ubb ubg ubo ubt ubu uga ugb ugg ugo ugt ugu uoa uob uog uoo uot uta utb uto utt utu uua uug uut uuu