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:
['3411', 'a', 'v', 'j', '8925', '909', 'h', 'l', 'r', '1371', 'u', '7789', '4813', 'u', 'q', 'i', '8473', 'n', '7191', 'c', '4641', 'e', '5107', 'q', 'z', 't', '105', 'q']

Ex Output:
a, c, e, h, i, j, l, n, q, r, t, u, v, z


Ex Input:
['i', 'x', 'n', 'w', '8915', 'd', 'd', 'd', '6025', '7861']

Ex Output:
d, i, n, w, x


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

Ex Output:

c, g, q, t, u, v, w, y