-ana aaaa aaab aaaf aaan aaba aabb aafa aafb aaff aana aaon aaoo abaa abab abaf aban abb- abba abbb abbo abff aboa abob abof abon aboo afaa afan afao affa affo afoa afoo ana- anaa anab anan anao anba anbb anbo anfa anfo anna annb anno ano- anoa anon aoba aonb aono baaa baaf baan baba babb babo baff bafo bana bann bano baon bbbb bbfn boab boan boba bobb bobo bofa boff bona bonn bono boob boof boon faaa faan faba fabo fafa faff fafo fana fano faon ffff foaf foan foba fofo fono foof foon naaa naab naan naba nabf nabo nafa naff nafo nan- nana nanb nann nano nbaa nbaf nbbo nbfa nfaa nfff nfon nnnn noaa noba nobo non- nona nonn nono noo- noob noon nooo oafo oban obba obbo obon ofan off- offa offo ofna ofno onab onan onna onno onon ooaa ooba ooff oona oooo