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: Consider Input: ['7013', '8755', 'u', '9377', 'n', '6997', '507', '8557', '9745', 'g', '3019', '93', 'l', '1219', 'a', '393', '2573', 'q', 'b', '6101', 'e']

Output: a, b, e, g, l, n, q, u


Input: Consider Input: ['s', 'u']

Output: s, u


Input: Consider Input: ['4875', '2283', '227', '5053', 'y']


Output: y