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:
['4637', 'f', '2639', '8623', 'w', 'e', 'k', '5503', 'x', '6633', '7553', '1455', 'u', '1773', 'r', 'u', '1489', 'u', '1303', '9683', 'z', '565', '7041', 'x', 'z', '9431', 'k', 'v', 'j', 'z', '5469', '5665', '4089', '4951', '8263', '5675', '4095', '7745', 'z', '2437', 'd', 'e', 'w']

Ex Output:
d, e, f, j, k, r, u, v, w, x, z


Ex Input:
['s', 'c', 'e', '2457', '9413', 'r', '9949', 's', 'z', 'e', 'a', 'o', '7207']

Ex Output:
a, c, e, o, r, s, z


Ex Input:
['d', 'z', 'g', 'l', 'w', '7651', '5109', 'z', '3889', '4425', '4373', 'l', 'h', 'y', 'i', '7271', '259', '3873', 'p', 'v', '6619', 'y', '4145', 't', '7527', '4937', '9177', '5909', 'q', '6139', '3757', 'q']

Ex Output:

d, g, h, i, l, p, q, t, v, w, y, z