a-a a-b a-t aaa aab aad aae aak aat ab- aba abb abd abe abk abt ad- ada adb add ade adk adt aea aeb aed aee aek aet aka akb akd ake akk at- ata atb atd ate att baa bab bad bae bak bat bba bbb bbd bbe bbk bbt bda bdb bdd bde bdk bdt be- bea beb bed bee bek bet bka bkb bke bkk bkt bta btb btd bte btk btt daa dab dad dae dak dat dba dbb dbd dbe dbk dbt dda ddb ddd dde ddk ddt de- dea deb ded dee dek det dka dkb dke dkk dkt dta dtb dtd dte dtk dtt eaa eab ead eae eak eat eba ebb ebd ebe ebk ebt ed- eda edb edd ede edk edt eea eeb eed eee eek eet eka ekb ekd eke ekt eta etb etd ete etk ett k-t ka- kaa kab kad kae kak kat kba kbb kbd kbe kbk kda kdb kde kdk kdt ke- kea keb ked kee kek ket kkb kke kkk kkt kta ktb kte ktk ktt taa tab tad tae tak tat tba tbb tbd tbe tbk tbt tda tdb tdd tde tdk tdt te- tea teb ted tee tek tet tka tkb tke tkk tkt tta ttb ttd tte ttk ttt