a-a a-b a-t aaa aab aad aae aan aat ab- aba abb abd abe abn abt ad- ada adb add ade adn adt aea aeb aed aee aen aet an- ana anb and ane ann ant at- ata atb atd ate atn att baa bab bad bae ban bat bba bbb bbd bbe bbn bbt bda bdb bdd bde bdt be- bea beb bed bee ben bet bna bnb bnd bne bnn bnt bta btb btd bte btn btt daa dab dad dae dan dat dba dbb dbd dbe dbn dbt dda ddb ddd dde ddn ddt de- dea deb ded dee den det dna dnb dnd dne dnn dnt dta dtb dtd dte dtn dtt eaa eab ead eae ean eat eba ebb ebd ebe ebn ebt ed- eda edb edd ede edn edt eea eeb eed eee een eet en- ena enb end ene enn ent eta etb etd ete etn ett naa nab nad nae nan nat nba nbb nbd nbe nbn nbt nda ndb ndd nde ndn ndt ne- nea neb ned nee nen net nna nnb nne nnn nnt nta ntb ntd nte ntn ntt taa tab tad tae tan tat tba tbb tbd tbe tbn tbt tda tdb tdd tde tdn tdt te- tea teb ted tee ten tet tna tnb tnd tne tnn tnt tta ttb ttd tte ttn ttt