a-do aaaa aaab aaad aaap aaba aabb aabd aabp aada aaoo aapa aapo abaa abab abad abap abb- abba abbb abbo abda abdo aboa abob abod aboo abpa abpd abpp adaa adab adad adao adap adba adda addd addo adob adod adoo adp- aoba aopo apao apap apba apda apdd apo- apod apoo apop appa appd baaa baad baba babb babo bada badb badd bado bapa bapp bbad bbbb bbdd bbdo boab boad boba bobb bobo boda bodb bodo boob bood boop bopa bopp bpda d-bo daab daad daap daba dabb dabo dabp dada dado dapa dapp dbpd dddd ddpo doab doap doba dobb dod- doda dodd dodo doob dood doop dopa dopo dopp dpaa dppa obad obba obbo odbo odda oddd odoo odop ooaa ooba ooda oooo opap opo- oppa oppo paap paba pada padd pado papa papb papp pbpa pdpa poad poba pobo pod- poda podd podo pood poop pop- popa popo popp ppad ppap ppoa ppod pppa pppd pppo pppp