a-a a-b a-t aaa aab aat aau aav ab- aba abb abt abu abv at- ata atb att atu atv au- aua aub aut auv av- ava avb avt avu b-u baa bab bat bau bav bba bbb bbt bbu bta btb btt btu btv bua bub but buu bva bvb bvt bvu bvv taa tab tat tau tav tba tbb tbt tbu tbv tta ttb ttt ttu ttv tua tub tut tuu tuv tva tvb tvt tvu ua- uaa uab uat uau uav uba ubb ubt ubu ubv uta utb utt utu utv uua uut uuu uva uvb uvu uvv v-a vaa vab vat vau vav vba vbv vta vtb vtt vtu vtv vut vuv vva vvb vvt vvv