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.

Ex Input:
['9555', '5983', '1853', 'c', 'z', 't', 'p', '9041', 'd', '5919', '1621', '345', 's', '2647', '4261', '8611', 'w', 'x', 'p', '9103', '2599', '5101', '9261', 'k', '7437']

Ex Output:
c, d, k, p, s, t, w, x, z


Ex Input:
['a', '3281', '9123', '5443', 'w', 'w', 'p', '9275', 'v', 'm', '3549', 'l', 'y', 'l']

Ex Output:
a, l, m, p, v, w, y


Ex Input:
['4115', '5239', '3845', 'q', '2887', 'r', '8795', '539', '4837', 'm', 'x', 'k', '7473', 'x', '9047', 'f', '4695', 'f', '3423', 'g']

Ex Output:

f, g, k, m, q, r, x