a-a a-b a-t aaa aab aad aae aak aan aat ab- aba abb abd abe abk abn abt ad- ada adb add ade adk adn adt aea aeb aed aee aek aen aet aka akb akd ake akk akn an- ana anb and ane ank ann ant at- ata atb atd ate atn att baa bab bad bae bak ban bat bba bbb bbd bbe bbk bbn bbt bda bdb bdd bde bdk bdt be- bea beb bed bee bek ben bet bka bkb bke bkk bkn bkt bna bnb bnd bne bnk bnn bnt bta btb btd bte btk btn btt daa dab dad dae dak dan dat dba dbb dbd dbe dbk dbn dbt dda ddb ddd dde ddk ddn ddt de- dea deb ded dee dek den det dka dkb dke dkk dkt dna dnb dnd dne dnk dnn dnt dta dtb dtd dte dtk dtn dtt eaa eab ead eae eak ean eat eba ebb ebd ebe ebk ebn ebt ed- eda edb edd ede edk edn edt eea eeb eed eee eek een eet eka ekb ekd eke ekt en- ena enb end ene enk enn ent eta etb etd ete etk etn ett k-t ka- kaa kab kad kae kak kan kat kba kbb kbd kbe kbk kbn kda kdb kde kdk kdt ke- kea keb ked kee kek ken ket kkb kke kkk kkn kkt kn- kna knd kne knk knn knt kta ktb kte ktk ktn ktt naa nab nad nae nak nan nat nba nbb nbd nbe nbk nbn nbt nda ndb ndd nde ndk ndn ndt ne- nea neb ned nee nek nen net nka nke nkk nkn nkt nna nnb nne nnk nnn nnt nta ntb ntd nte ntk ntn ntt taa tab tad tae tak tan tat tba tbb tbd tbe tbk tbn tbt tda tdb tdd tde tdk tdn tdt te- tea teb ted tee tek ten tet tka tkb tke tkk tkt tna tnb tnd tne tnk tnn tnt tta ttb ttd tte ttk ttn ttt