a-a a-b aaa aab aad aae aau aax ab- aba abb abd abe abu abx ad- ada adb add ade adu adx aea aeb aed aee aeu aex au- aua aub aud aue aux ax- axa axe axx b-u baa bab bad bae bau bax bba bbb bbd bbe bbu bbx bda bdb bdd bde bdu bdx be- bea beb bed bee beu bex bua bub bud bue buu bux bxb bxd bxx daa dab dad dae dau dax dba dbb dbd dbe dbu dbx dda ddb ddd dde ddu ddx de- dea deb ded dee deu dex dua dub dud due dux dxd dxx eaa eab ead eae eau eax eba ebb ebd ebe ebu ebx ed- eda edb edd ede edu edx eea eeb eed eee eex eu- eua eub eud eue eux ex- exa exd exe exu exx ua- uaa uab uad uae uau uba ubb ube ubu ubx uda udb udd ude udu udx uea ueb ued uee uua uue uuu uxb uxu xaa xad xau xbe xbx xda xdb xde xed xee xeu xex xue xxx