a-a a-b aaa aab aad aae aah aak ab- aba abb abd abe abh abk ad- ada adb add ade adh adk aea aeb aed aee aeh aek aha ahb ahd ahe ahh ahk aka akb akd ake akh akk baa bab bad bae bah bak bba bbb bbd bbe bbh bbk bda bdb bdd bde bdh bdk be- bea beb bed bee beh bek bha bhb bhd bhe bhh bhk bka bkb bke bkk daa dab dad dae dah dak dba dbb dbd dbe dbh dbk dda ddb ddd dde ddh ddk de- dea deb ded dee deh dek dh- dha dhb dhd dhe dhh dhk dka dkb dke dkk eaa eab ead eae eah eak eba ebb ebd ebe ebh ebk ed- eda edb edd ede edh edk eea eeb eed eee eek eha ehb ehd ehe ehh eka ekb ekd eke ekh haa hab had hae hah hak hba hbb hbd hbe hbh hbk hda hdb hdd hde hdh hdk he- hea heb hed hee heh hek hha hhb hhd hhe hhh hhk hka hkb hkd hkh hkk ka- kaa kab kad kae kah kak kba kbb kbd kbe kbh kbk kda kdb kde kdh kdk ke- kea keb ked kee keh kek kha khe khh khk kkb kke kkh kkk