-al a-a a-b a-c aaa aab aac aae aak aal ab- aba abb abc abe abk abl ac- aca acb acc ace ack acl aea aeb aec aee aek ael aka akb akc ake akk akl al- ala alb alc ale alk all baa bab bac bae bak bal bba bbb bbc bbe bbk bbl bca bcb bcc bce bck bcl be- bea beb bec bee bek bel bka bkb bkc bke bkk bkl bla blb blc ble blk bll c-- caa cab cac cae cak cal cba cbb cbc cbe cbk cbl cca ccb ccc cce cck ccl ce- cea ceb cec cee cek cel cka ckb ckc cl- cla clb clc cle clk cll eaa eab eac eae eak eal eba ebb ebc ebe ebk ebl ec- eca ecb ecc ece eck ecl eea eeb eec eee eek eel eka ekb ekc eke ekl ela elb elc ele elk ell ka- kaa kab kac kae kak kal kba kbb kbc kbe kbk kbl kca kcb kcc kce kck kcl ke- kea keb kec kee kek kel kkb kkc kke kkk kkl kl- kla klb klc la- laa lab lac lae lak lal lba lbb lbc lbe lbk lbl lca lcb lcc lce lck lcl lea leb lec lee lek lel lka lkb lkl lla llb llc lle llk lll