a-a a-b aaa aab aad aae aau ab- aba abb abd abe abu ad- ada adb add ade adu aea aeb aed aee aeu au- aua aub aud aue b-u baa bab bad bae bau bba bbb bbd bbe bbu bda bdb bdd bde bdu be- bea beb bed bee beu bua bub bud bue buu daa dab dad dae dau dba dbb dbd dbe dbu dda ddb ddd dde ddu de- dea deb ded dee deu dua dub dud due eaa eab ead eae eau eba ebb ebd ebe ebu ed- eda edb edd ede edu eea eeb eed eee eu- eua eub eud eue ua- uaa uab uad uae uau uba ubb ube ubu uda udb udd ude udu uea ueb ued uee uua uue uuu