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.

Example Input: ['k', 'v', 'e', '6377', 'y', '3585', '4535', 'f', 'g', 'm', 'f', '8369', 'v', '7445', '4527', '9383', 'n']
Example Output: e, f, g, k, m, n, v, y

Example Input: ['f', '3409', 'i', '4147', '1745', '6007', 'l', 'd', 'i']
Example Output: d, f, i, l

Example Input: ['923', 'g', 'x', 'o', '1975', 'x', 'b', 'l', '575']
Example Output:
b, g, l, o, x

