aaaa aaab aaad aaba aabb aabd aabt aada aadt aadu aata aatt abaa abab abad abat abau abb- abba abbb abbt abda abdu abta abtu abua abud abut adaa adab adad adat adba adda addd addu adta adua adub at-t ataa atab atad atat atdt atta attu atua atub auaa aut- baaa baad baat baba babb babu bada badb badd badu bata batt batu bau- baud bbad bbau bbbb bbdd btaa btdt bttb buad buat buba bubb bubu buda budb budd budu but- buta butt daab daad daau daba dabb dabt dabu dada dadu data datt datu daub daud daut dbtt dddd ddub dtaa duaa duab duad duat dub- duba dubb dubu duda dudd dudu duta duut taa- taat taba tabb tabu tada tata tatb tatt tatu taua taub taut tbta tddb ttab ttbb tttt tuat tuba tubb tubu tudu tuta tutt tutu uata uatu uaua ubba ubud udaa udad udau utau uttu uuta uuuu