a-a a-b a-t aaa aab aan aat aaw ab- aba abb abn abt abw an- ana anb ann ant at- ata atb atn att atw aw- awa awb awn awt aww baa bab ban bat baw bba bbb bbn bbt bbw bna bnb bnn bnt bnw bta btb btn btt btw bwa bwb naa nab nan nat naw nba nbb nbn nbt nbw nna nnb nnn nnt nnw nta ntb ntn ntt nwa nwb nwn nwt taa tab tan tat taw tba tbb tbn tbt tna tnb tnn tnt tnw tta ttb ttn ttt ttw twa twb twn twt tww waa wab wan wat waw wba wbb wbn wbt wbw wn- wna wnn wnt wnw wta wtb wtn wtt wtw wwa wwn wwt www