a-a a-b a-t aaa aab aae aat aau aax ab- aba abb abe abt abu abx aea aeb aee aet aeu aex at- ata atb ate att atu atx au- aua aub aue aut aux ax- axa axe axt axx b-u baa bab bae bat bau bax bba bbb bbe bbt bbu bbx be- bea beb bee bet beu bex bta btb bte btt btu btx bua bub bue but buu bux bxb bxx eaa eab eae eat eau eax eba ebb ebe ebt ebu ebx eea eeb eee eet eex eta etb ete ett etu etx eu- eua eub eue eut eux ex- exa exe ext exu exx t-x taa tab tae tat tau tax tba tbb tbe tbt tbu te- tea teb tee tet teu tex tta ttb tte ttt ttu ttx tua tub tue tut tuu tux txe txt txu ua- uaa uab uae uat uau uba ubb ube ubt ubu ubx uea ueb uee uet uta utb ute utt utu utx uua uue uut uuu uxb uxt uxu xaa xat xau xbe xbx xee xet xeu xex xtx xue xxx