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:
['f', 'w', 'y', 't', '5269', '9989', 'p', 'v', '6609', 'v', 'c', 'q', 'm', '6565', '189', 'm', '3617', 'b', '9147', '665', 'v', '5989', '1511', '3123', '6667', '4661', '185', 'b', '3405', 'b', '6027', 'n', '6973', '505', 'g', '815', '3439', '2069', '291', 'j', 'f', '1121', '8009', 'm', '8353']

Ex Output:
b, c, f, g, j, m, n, p, q, t, v, w, y


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:
['a', 'w', 'm', 'g', 'c', '5475', '7391', 't', '1049', 'p', 'd', '1397', 'k', 'x', 'j', '2525', 'f', '741']

Ex Output:

a, c, d, f, g, j, k, m, p, t, w, x