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: ['c', 'e', '6509', '1295', 'u', '5445', '1731', '3049']
Example Output: c, e, u

Example Input: ['4213', '3595', '7937', 'y', '5723', 'v', 'b', '7007']
Example Output: b, v, y

Example Input: ['1493', '3069', 'l', 'r', '4277', '6017', 'e', 'x', '1509', '6697', 's', 'l', '4815', 'z', 'n', '6529', 'r', '2615', 's', '3987', 'f', '5261', '2279', 'm', 'z', 'k', '7479', 's', 'g', 'k', 'c', 'm', 'z']
Example Output:
c, e, f, g, k, l, m, n, r, s, x, z