a-a a-b a-c aaa aab aac aad aae aah aak ab- aba abb abc abd abe abh abk ac- aca acb acc acd ace ach ack ad- ada adb adc add ade adh adk aea aeb aec aed aee aeh aek aha ahb ahc ahd ahe ahh ahk aka akb akc akd ake akh akk baa bab bac bad bae bah bak bba bbb bbc bbd bbe bbh bbk bca bcb bcc bcd bce bch bck bda bdb bdc bdd bde bdh bdk be- bea beb bec bed bee beh bek bha bhb bhc bhd bhe bhh bhk bka bkb bkc bke bkk c-- caa cab cac cad cae cah cak cba cbb cbc cbd cbe cbh cbk cca ccb ccc ccd cce cch cck cda cdb cdc cdd cde cdh cdk ce- cea ceb cec ced cee ceh cek ch- cha chb chc chd che chh chk cka ckb ckc ckd ckh daa dab dac dad dae dah dak dba dbb dbc dbd dbe dbh dbk dca dcb dcc dcd dce dck dda ddb ddc ddd dde ddh ddk de- dea deb dec ded dee deh dek dh- dha dhb dhc dhd dhe dhh dhk dka dkb dkc dke dkk eaa eab eac ead eae eah eak eba ebb ebc ebd ebe ebh ebk ec- eca ecb ecc ecd ece ech eck ed- eda edb edc edd ede edh edk eea eeb eec eed eee eek eha ehb ehc ehd ehe ehh eka ekb ekc ekd eke ekh haa hab hac had hae hah hak hba hbb hbc hbd hbe hbh hbk hca hcb hcc hcd hce hch hck hda hdb hdc hdd hde hdh hdk he- hea heb hec hed hee heh hek hha hhb hhc hhd hhe hhh hhk hka hkb hkd hkh hkk ka- kaa kab kac kad kae kah kak kba kbb kbc kbd kbe kbh kbk kca kcb kcc kcd kce kch kck kda kdb kdc kde kdh kdk ke- kea keb kec ked kee keh kek kha khe khh khk kkb kkc kke kkh kkk