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:
['7071', 'h', '837', 'z', 'c', '2217', 'c', '6341', '6607', 'g', '3569', 'a', 'h', 't', 'b', 'f', 'g', 'f', 'l', 'b', 'x', 'o', 'r', '8949', '8071', '1507', 'v']

Ex Output:
a, b, c, f, g, h, l, o, r, t, v, x, z


Ex Input:
['57', 'j', 'n', '877', 'u', 'w', 'j', 'f', '8977', 'h', '469', '9417']

Ex Output:
f, h, j, n, u, w


Ex Input:
['3863', '9115', '5211', '6335', '3119', '5319', 'd', 's', 'y', 'w', '9985', '7805', 't', 'b', '8601', '7625', 'u', 'f', '9139', '5381', '9275', '9267', '8383', '5883', 'r', '4605']

Ex Output:

b, d, f, r, s, t, u, w, y