a-be aaaa aaab aaae aaba aabb aabt aaea aata aatt abaa abab abae abat abau abb- abba abbb abbe abbt abee abet abta abtu abua abue abut aeta aett at-t ataa atab atae atat atea atee atta atte attu atua atub auaa aube aut- aute baaa baat baba babb babe babu bata bate batt batu bau- bbau bbbb bbeb bbet beat beau beba bebb bebe beeb beet beta bete bett betu btaa bttb buat buba bubb bube bubu buea bueu but- buta bute butt eaba eata eate ebba eeea eeee eeta eete eetu etat etee etta ette ettu etua euba taa- taat taba tabb tabe tabu tata tatb tate tatt tatu taua taub taue taut tbta teat teba tebu teet teta tete tett tetu teut ttab ttbb tttt tuae tuat tuba tubb tube tubu tuet tuta tute tutt tutu uata uatu uaua ubba ubbe ubet ueba utau uttu uuta uuuu