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:
['6181', 'w', '4663', '5507', 'a', '6607', '869', '2669', 'r', '3629', 'r', 'l', '6599', '8885', 's', '4315', 'z', 'l', 'r', '1225', '8371', '1545', '7169', '1175', 'k', 'p', 'y', '7263', '5537', '8649', '3317', 'q', 'r', 'u', 'd', '4647', 'u', 'y', 'h', '9753', 'q', '725']

Ex Output:
a, d, h, k, l, p, q, r, s, u, w, y, z


Ex Input:
['4993', '6641', '3127', '9409', '8453', '5909', '6109', 'y', 'f', '6859', 'c', '3863', 't', '1221', '3689', 'w', 'h', '7947', 't', '5979', 'l', 'i', '1321', '3149', 'l', 'v', '3825', 'z', '9297', 'f', 'e', '7205', 'a', 'a', '2645', '391', '4965', 'w', 'h', '7715', '9409', '3603', '4147']

Ex Output:
a, c, e, f, h, i, l, t, v, w, y, z


Ex Input:
['3267', 'f', 'a', '6897']

Ex Output:

a, f