a-a a-b aaa aab aad aae aan aao aau ab- aba abb abd abe abn abo abu ad- ada adb add ade adn ado adu aea aeb aed aee aen aeo aeu an- ana anb and ane ann ano anu aoa aob aod aoe aon aoo aou au- aua aub aud aue aun auo b-u baa bab bad bae ban bao bau bba bbb bbd bbe bbn bbo bbu bda bdb bdd bde bdo bdu be- bea beb bed bee ben beo beu bna bnb bnd bne bnn bno bnu boa bob bod boe bon boo bou bua bub bud bue bun buo buu daa dab dad dae dan dao dau dba dbb dbd dbe dbn dbo dbu dda ddb ddd dde ddn ddo ddu de- dea deb ded dee den deo deu dna dnb dnd dne dnn dno doa dob dod doe don doo dou dua dub dud due dun duo eaa eab ead eae ean eao eau eba ebb ebd ebe ebn ebo ebu ed- eda edb edd ede edn edo edu eea eeb eed eee een eeo en- ena enb end ene enn eno enu eo- eoa eob eod eoe eon eoo eou eu- eua eub eud eue eun naa nab nad nae nan nao nau nba nbb nbd nbe nbn nbo nbu nda ndb ndd nde ndn ndo ndu ne- nea neb ned nee nen neo neu nna nnb nne nnn nno nnu no- noa nob nod noe non noo nou nua nub nud nue nun nuo nuu oaa oab oad oae oan oao oau ob- oba obb obd obe obn obo obu oda odb odd ode odn odo odu oea oeb oed oee oen oeo on- ona onb ond one onn ono onu oo- ooa oob ood oon ooo ou- oua oud oue oun ouo ua- uaa uab uad uae uan uao uau uba ubb ube ubn ubo ubu uda udb udd ude udn udo udu uea ueb ued uee uen un- una unb und une unn uno unu uoa uob uod uoe uon uoo uua uue uun uuu