a-do aaaa aaab aaad aaav aaba aabb aabd aada aaoo aava abaa abab abad abb- abba abbb abbo abda abdo aboa abob abod aboo abov abva abvd adaa adab adad adao adba adda addd addo adob adod adoo advb aoba avab avao avda avva avvo baaa baad baba babb babo bada badb badd bado bava bbad bbbb bbdd bbdo bdav boab boad boba bobb bobo boda bodb bodo boob bood bova bovo d-bo daab daad daba dabb dabo dada dado dava dddd doab doba dobb dod- doda dodd dodo doob dood dvda dvoa obad obba obbo odbo odda oddd odoo odva ooaa ooba ooda oooo ovda ovo- ovod ovoo vaad vada vado vava voad voda vodo vvob vvvv