-al a-a a-b a-c aaa aab aac aae aaf aal ab- aba abb abc abe abf abl ac- aca acb acc ace acf acl aea aeb aec aee aef ael af- afa afb afc afe aff afl al- ala alb alc ale alf all baa bab bac bae baf bal bba bbb bbc bbe bbf bbl bca bcb bcc bce bcf bcl be- bea beb bec bee bef bel bfa bfb bfc bfe bff bfl bla blb blc ble blf bll c-- caa cab cac cae caf cal cba cbb cbc cbe cbf cbl cca ccb ccc cce ccf ccl ce- cea ceb cec cee cef cel cfa cfb cfc cfe cff cfl cl- cla clb clc cle clf cll eaa eab eac eae eaf eal eba ebb ebc ebe ebf ebl ec- eca ecb ecc ece ecf ecl eea eeb eec eee eef eel ef- efa efb efc efe eff efl ela elb elc ele elf ell faa fab fac fae faf fal fba fbb fbc fbe fbf fbl fca fcb fcc fce fcf fcl fea feb fec fee fef fel ffa ffc ffe fff ffl fla flb flc fle flf fll la- laa lab lac lae laf lal lba lbb lbc lbe lbf lbl lca lcb lcc lce lcf lcl lea leb lec lee lef lel lfa lfb lfc lfe lff lfl lla llb llc lle llf lll