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:
['6209', 'x', 'j', 'w', '7965', '4905', '6297', '4291', '7183', 'a', 'l', '5267', 'r', '5935', 'a', '7865', 'h', 'p', '6117', 'a', 'y', 'y', 't', 'v', '7271', 'e', 'e', 'z', 'i', 'l', '4731', '2059', 'm', '5703', 'k', 'f', '8125', 'e', '7569', 'r', '2287', '593']

Ex Output:
a, e, f, h, i, j, k, l, m, p, r, t, v, w, x, y, z


Ex Input:
['4009', 'y', '9077', 'p', 'q', '6711', '6443', '5491']

Ex Output:
p, q, y


Ex Input:
['5357', '9785', '2157', '9203', '1705', 'd', 'y', '9867', '2251', '1875', 's', '3161', '2411', 'z', '7475', 'n', 's', 'b', '1281', 'n', 'w', '6401', 'l', 'b', 's', 'y', 'r', 'o', '8397', '4477', '827']

Ex Output:

b, d, l, n, o, r, s, w, y, z