a-a a-b aaa aab aad aae aaf aah ab- aba abb abd abe abf abh ad- ada adb add ade adf adh aea aeb aed aee aef aeh af- afa afb afd afe aff afh aha ahb ahd ahe ahf ahh baa bab bad bae baf bah bba bbb bbd bbe bbf bbh bda bdb bdd bde bdf bdh be- bea beb bed bee bef beh bfa bfb bfd bfe bff bfh bha bhb bhd bhe bhf bhh daa dab dad dae daf dah dba dbb dbd dbe dbf dbh dda ddb ddd dde ddf ddh de- dea deb ded dee def deh dfa dfb dfd dfe dff dfh dh- dha dhb dhd dhe dhf dhh eaa eab ead eae eaf eah eba ebb ebd ebe ebf ebh ed- eda edb edd ede edf edh eea eeb eed eee eef ef- efa efb efd efe eff efh eha ehb ehd ehe ehf ehh faa fab fad fae faf fah fba fbb fbd fbe fbf fbh fda fdb fdd fde fdf fdh fea feb fed fee fef feh ffa ffd ffe fff ffh fha fhb fhe fhf fhh haa hab had hae haf hah hba hbb hbd hbe hbf hbh hda hdb hdd hde hdf hdh he- hea heb hed hee hef heh hfa hfb hfd hfe hff hfh hha hhb hhd hhe hhf hhh