a-be aaaa aaab aaae aaav aaba aabb aabt aaea aaev aata aatt aava abaa abab abae abat abb- abba abbb abbe abbt abee abet abta abva aeta aett aeva at-t ataa atab atae atat atea atee atta atte avab avat avea avva baaa baat baba babb babe bata bate batt bava bave bbbb bbeb bbet beat beav beba bebb bebe beeb beet beta bete bett betv btaa bttb eaba eata eate eave ebba eeea eeee eeta eete eeva etat etee etta ette evae evat evea evet taa- taat taba tabb tabe tata tatb tate tatt tatv tava tave tbta teat teba teet teev teta tete tett teva ttab ttbb tttt tvtv vaat vata vate vatt vava veat veba veet veta vete veve vvvv