-al a-a a-b aaa aab aae aaf aak aal ab- aba abb abe abf abk abl aea aeb aee aef aek ael af- afa afb afe aff afk afl aka akb ake akk akl al- ala alb ale alf alk all baa bab bae baf bak bal bba bbb bbe bbf bbk bbl be- bea beb bee bef bek bel bfa bfb bfe bff bfl bka bkb bke bkf bkk bkl bla blb ble blf blk bll eaa eab eae eaf eak eal eba ebb ebe ebf ebk ebl eea eeb eee eef eek eel ef- efa efb efe eff efl eka ekb eke ekf ekl ela elb ele elf elk ell faa fab fae faf fak fal fba fbb fbe fbf fbk fbl fea feb fee fef fek fel ffa ffe fff ffk ffl fka fkb fkf fkk fkl fla flb fle flf fll ka- kaa kab kae kaf kak kal kba kbb kbe kbf kbk kbl ke- kea keb kee kef kek kel kfa kff kkb kke kkk kkl kl- kla klb klf la- laa lab lae laf lak lal lba lbb lbe lbf lbk lbl lea leb lee lef lek lel lfa lfb lfe lff lfk lfl lka lkb lkl lla llb lle llf llk lll