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: ['3651', 'c', 'm', '7123', '2981', '9649', 'o', '2181', 'h', '8577', 'a', '5027', 'x', 'u', '1039', '347', '8219', 'c', '1063', '8885', 'f', 'd', '3067', '2509', 'i', 's', '5509', '2003', 'h', '8869', 'x', 'd', '5141', 'h', 'i', 'b', 'o']
Example Output: a, b, c, d, f, h, i, m, o, s, u, x

Example Input: ['7997', 'm']
Example Output: m

Example Input: ['w', '977', '2317', 'm', '7709', 'y', '6353', '503', '5649', '4047', 'l', '1349', 'y', 'i', '6601', '8601', '7567', 'u', '9023', '3429', 'm']
Example Output:
i, l, m, u, w, y