Definition: In this task, you are given an input list A comprising of numbers and alphabets. You need to extract and sort the unique alphabets in the list. The alphabets in the input list will only be in lowercase. Return -1 if there is no alphabet in the input list.
Input: ['935', '73', 'x', '5249', '7401', '6981', '4779', '5445', 'g', 'e']

e, g, x