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:
['491', '229', 'g', '6677', '4793', 'h', 'x', 'a', '2333', 'u', 'l', '785', 'p', '7331', '653', '5193', '5415', '8417', 'v']

Ex Output:
a, g, h, l, p, u, v, x


Ex Input:
['1449', 'a', '6261', '303', '4651', 'n', 'u', '1595']

Ex Output:
a, n, u


Ex Input:
['5199', '1307', '1713', '3397', 'u', '6441', 'e', '3307', '7863', 'z', 'r', '1463', 'p', 'h', '8915', 'o', 'z', '5077', 'y', 'q', 'i', 'd', 'u', '6941', 'f', 'r', 'a', 'q']

Ex Output:

a, d, e, f, h, i, o, p, q, r, u, y, z