a-be aaaa aaab aaad aaae aaav aaba aabb aabd aada aade aaea aaev aava abaa abab abad abae abb- abba abbb abbe abda abed abee abva abvd adaa adab adad adae adba adda addd adde adea adeb adee advb aede aeva avab avda avea avva baaa baad baba babb babe bada badb badd bade baed bava bave bbad bbbb bbdd bbeb bdav bead beav beba bebb bebe beda bede beeb beed daab daad daae daba dabb dada dade daeb dava dave dddd dead deae deba debe deda dedd dede deeb deed deev deva deve dvda eaba eada eadb eadd eave ebba ebed edad edda edde ede- edea edve eede eeea eeee eeva evae evdb evea vaad vada vade vava veba veda vede veve vvvv