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:
['815', '6967', '6553', 'r', 'y', '3641', 'q', 'b', '6131', '4289', 'w', '6093', '6055', 'i', 'b', 'y', '5107', 'v', 'g', '9709', 'x', 'i']

Ex Output:
b, g, i, q, r, v, w, x, y


Ex Input:
['q', 'c', 'o', 'e', 'n', 'q', 'w', '9475', 'w', '863', 'r', '2219', '3483', '5035', '8209', '7957', 'b', '3735', '1423', 'l', '3409', '7639', 'd']

Ex Output:
b, c, d, e, l, n, o, q, r, w


Ex Input:
['7323', 'f', 'b', 'p', 'd', 'v', 'x', '1821', '6619', 'c', 's', '8695', 'h', '4229', '8761', '9689', '8723', '9307', 'm', 'v', 't', 'e', '7757', 'g', 'l', '253']

Ex Output:

b, c, d, e, f, g, h, l, m, p, s, t, v, x