a-ya aaaa aaab aaba aabb aabt aaby aata aatt abaa abab abat abax abay abb- abba abbb abbt abby abta abyt abyy at-t at-x ataa atab atat atax atay atta atty atya axat ayat ayay ayta ayya ba-x baaa baat baba babb baby bata batt baty baxt baya bayt bbay bbbb btaa bttb taa- taat taba tabb taby tata tatb tatt taty tax- taxa taxt taxy taya tayt tayy tbta ttab ttbb tttt txaa tyta tytt tyty tyxt xxxx xxxy yaba yata yaxa yaya ytay yyyy