a-a a-b a-t aaa aab aad aae aaf aat ab- aba abb abd abe abf abt ad- ada adb add ade adf adt aea aeb aed aee aef aet af- afa afb afd afe aff aft at- ata atb atd ate atf att baa bab bad bae baf bat bba bbb bbd bbe bbf bbt bda bdb bdd bde bdf bdt be- bea beb bed bee bef bet bfa bfb bfd bfe bff bft bta btb btd bte btf btt daa dab dad dae daf dat dba dbb dbd dbe dbf dbt dda ddb ddd dde ddf ddt de- dea deb ded dee def det dfa dfb dfd dfe dff dft dta dtb dtd dte dtf dtt eaa eab ead eae eaf eat eba ebb ebd ebe ebf ebt ed- eda edb edd ede edf edt eea eeb eed eee eef eet ef- efa efb efd efe eff eft eta etb etd ete etf ett faa fab fad fae faf fat fba fbb fbd fbe fbf fbt fda fdb fdd fde fdf fdt fea feb fed fee fef fet ffa ffd ffe fff fft fta ftb ftd fte ftf ftt taa tab tad tae taf tat tba tbb tbd tbe tbf tbt tda tdb tdd tde tdf tdt te- tea teb ted tee tef tet tfa tfb tfd tfe tff tft tta ttb ttd tte ttf ttt