a-a a-b a-c aaa aab aac aae aag aah aak ab- aba abb abc abe abg abh abk ac- aca acb acc ace acg ach ack aea aeb aec aee aeg aeh aek ag- aga agb agc age agg agh agk aha ahb ahc ahe ahg ahh ahk aka akb akc ake akg akh akk baa bab bac bae bag bah bak bba bbb bbc bbe bbg bbh bbk bca bcb bcc bce bcg bch bck be- bea beb bec bee beg beh bek bga bgb bgc bge bgg bgh bgk bha bhb bhc bhe bhg bhh bhk bka bkb bkc bke bkg bkk c-- caa cab cac cae cag cah cak cba cbb cbc cbe cbg cbh cbk cca ccb ccc cce ccg cch cck ce- cea ceb cec cee ceg ceh cek cga cgb cgc cge cgg cgh ch- cha chb chc che chg chh chk cka ckb ckc ckh eaa eab eac eae eag eah eak eba ebb ebc ebe ebg ebh ebk ec- eca ecb ecc ece ecg ech eck eea eeb eec eee eeg eek ega egb egc ege egg egh eha ehb ehc ehe ehg ehh eka ekb ekc eke ekg ekh gaa gab gac gae gag gah gak gba gbc gbe gbg gbh gbk gca gcb gcc gce gcg gch gck ge- gea geb gec gee geg geh gek gga ggb ggc ggg ggh gha ghb ghc ghe ghg ghh gka gkb gkh haa hab hac hae hag hah hak hba hbb hbc hbe hbg hbh hbk hca hcb hcc hce hcg hch hck he- hea heb hec hee heg heh hek hga hgb hgc hge hgg hgh hgk hha hhb hhc hhe hhg hhh hhk hka hkb hkg hkh hkk ka- kaa kab kac kae kag kah kak kba kbb kbc kbe kbh kbk kca kcb kcc kce kcg kch kck ke- kea keb kec kee keg keh kek kga kgb kgc kgh kha khe khh khk kkb kkc kke kkh kkk