a-a a-b aaa aab aad aan aao aau ab- aba abb abd abn abo abu ad- ada adb add adn ado adu an- ana anb and ann ano anu aoa aob aod aon aoo aou au- aua aub aud aun auo b-u baa bab bad ban bao bau bba bbb bbd bbn bbo bbu bda bdb bdd bdo bdu bna bnb bnd bnn bno bnu boa bob bod bon boo bou bua bub bud bun buo buu daa dab dad dan dao dau dba dbb dbd dbn dbo dbu dda ddb ddd ddn ddo ddu dna dnb dnd dnn dno doa dob dod don doo dou dua dub dud dun duo naa nab nad nan nao nau nba nbb nbd nbn nbo nbu nda ndb ndd ndn ndo ndu nna nnb nnn nno nnu no- noa nob nod non noo nou nua nub nud nun nuo nuu oaa oab oad oan oao oau ob- oba obb obd obn obo obu oda odb odd odn odo odu on- ona onb ond onn ono onu oo- ooa oob ood oon ooo ou- oua oud oun ouo ua- uaa uab uad uan uao uau uba ubb ubn ubo ubu uda udb udd udn udo udu un- una unb und unn uno unu uoa uob uod uon uoo uua uun uuu