a-a aaa aad aaf aan aao ad- ada add adf adn ado af- afa afd aff afn afo an- ana and anf ann ano aoa aod aof aon aoo daa dad daf dan dao dda ddd ddf ddn ddo dfa dfd dff dfn dfo dna dnd dnf dnn dno doa dod dof don doo faa fad faf fan fao fda fdd fdf fdn fdo ffa ffd fff ffn ffo fna fnd fnf fnn foa fof fon foo naa nad naf nan nao nda ndd ndf ndn ndo nfa nfd nff nfn nfo nna nnf nnn nno no- noa nod nof non noo oaa oad oaf oan oao oda odd odf odn odo of- ofa ofd off ofn ofo on- ona ond onf onn ono oo- ooa ood oof oon ooo