a-a a-b a-c aaa aab aac aae aah aax ab- aba abb abc abe abh abx ac- aca acb acc ace ach acx aea aeb aec aee aeh aex aha ahb ahc ahe ahh ahx ax- axa axe axh axx baa bab bac bae bah bax bba bbb bbc bbe bbh bbx bca bcb bcc bce bch bcx be- bea beb bec bee beh bex bha bhb bhc bhe bhh bhx bxb bxx c-- caa cab cac cae cah cax cba cbb cbc cbe cbh cbx cca ccb ccc cce cch ccx ce- cea ceb cec cee ceh cex ch- cha chb chc che chh chx cxc cxh cxx eaa eab eac eae eah eax eba ebb ebc ebe ebh ebx ec- eca ecb ecc ece ech ecx eea eeb eec eee eex eha ehb ehc ehe ehh ex- exa exc exe exh exx haa hab hac hae hah hax hba hbb hbc hbe hbh hbx hca hcb hcc hce hch he- hea heb hec hee heh hex hha hhb hhc hhe hhh hxc xaa xac xbc xbe xbx xcb xch xcx xee xex xxx