-al a-a a-b aaa aab aaf aak aal ab- aba abb abf abk abl af- afa afb aff afk afl aka akb akk akl al- ala alb alf alk all baa bab baf bak bal bba bbb bbf bbk bbl bfa bfb bff bfl bka bkb bkf bkk bkl bla blb blf blk bll faa fab faf fak fal fba fbb fbf fbk fbl ffa fff ffk ffl fka fkb fkf fkk fkl fla flb flf fll ka- kaa kab kaf kak kal kba kbb kbf kbk kbl kfa kff kkb kkk kkl kl- kla klb klf la- laa lab laf lak lal lba lbb lbf lbk lbl lfa lfb lff lfk lfl lka lkb lkl lla llb llf llk lll