-al a-a a-b aaa aab aae aal aax ab- aba abb abe abl abx aea aeb aee ael aex al- ala alb ale all alx ax- axa axe axl axx baa bab bae bal bax bba bbb bbe bbl bbx be- bea beb bee bel bex bla blb ble bll blx bxb bxl bxx eaa eab eae eal eax eba ebb ebe ebl ebx eea eeb eee eel eex ela elb ele ell elx ex- exa exe exl exx la- laa lab lae lal lax lba lbb lbe lbl lbx lea leb lee lel lex lla llb lle lll lxx xaa xal xbe xbl xbx xee xel xex xla xlb xxl xxx