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:
['w', '6291', '3939', '9569', 'u', '1635', '3359', '8335', 'n', '2799', '7359', 'k', 'm', '2817']

Ex Output:
k, m, n, u, w


Ex Input:
['1345', 'y', '7221', 'h', 'r', '3255', 'k', 'r', 'j', '8639', '467', 'f', 'k', 'n', 'k', 'j', 'l', 'w', '143', 'w', 'q', '5657', '589']

Ex Output:
f, h, j, k, l, n, q, r, w, y


Ex Input:
['3135', '4581', 'w', '4525', 'q', 'p', 'u', '3571', 'a', 'd', 'f', 'r', '5145', '2213', 'a', '1603', 'j', 'o', '2867', 'i', '5477', '6913', '1439', '2291', '4907', '4719', '1059', 'w', '6259', '1267', '4941', '3187', 'w', 'i', '8227', '3719', 'i', '6173', '7119', '6189', '497', '8283', 'n']

Ex Output:

a, d, f, i, j, n, o, p, q, r, u, w