a-a a-b a-t aaa aab aat aau aay ab- aba abb abt abu aby at- ata atb att atu au- aua aub aut ay- aya ayt ayu b-u baa bab bat bau bay bba bbb bbt bbu bby bta btb btt btu bty bua bub but buu buy by- bya byt byu taa tab tat tau tay tba tbb tbt tbu tta ttb ttt ttu tty tua tub tut tuu tuy tya tyt ua- uaa uab uat uau uay uba ubb ubt ubu uby uta utb utt utu uty uua uut uuu uyu yaa yab yat yau yay yby yta ytt ytu yua yut yuu yuy yyb yyt yyu yyy