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:
['u', '1805', 'l', 'l', '5449', 'r', '4471', 'a', 'u', 'c', 'q', '6463', '6717', '7025', '9359', 'q', 'h', '1989', '5497', 'h', 'd', 'c', '135', '5737', '1235', 'v', 'u', 'g', 'p', 't', '9223', '8289', '4489', 'n']

Ex Output:
a, c, d, g, h, l, n, p, q, r, t, u, v


Ex Input:
['g', 'u', 'q', '1375', '9491', 't', 'w', 'c', 'v', 'y', '3169', '1607']

Ex Output:
c, g, q, t, u, v, w, y


Ex Input:
['5397', '1785', 'c', '6739', '5303', 'w', 'i', 'h', '1599', 'n', 'm', 'n', 'o', 's', '6615', 'o', 'u', '4529', 'm', 'i', 'z', '6001', 'w', '6751', 'v', '3017', '6499', 'c', '8263', 'a', '8793', '8653']

Ex Output:

a, c, h, i, m, n, o, s, u, v, w, z