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.
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Question: ['s', 's', '3619', '6051', 'h', '213', '3937', 'v', 'p', 'y', '8449', '9337', '5327', 'a', 'a', 'w', '3985', 'n', 'm']

Answer: a, h, m, n, p, s, v, w, y


Question: ['5159', '6407', '4021', '6655', 'c', 'k', 'w', '7191', 'l', '4321', '1609', 'm', '1991', '9261', '511', 'p', '7495', 'b', 'e', '4647', '2711', 'd', 'y', '3835', '5037', '3613', '2695', '3367', 'm', 'j', 'y', '9561', '4889', 'a', 'z', '2253', 'p', 't', 's', '8371', '2859', 's']

Answer: a, b, c, d, e, j, k, l, m, p, s, t, w, y, z


Question: ['x', 'a', 'v', 'z', 'a', 'o', 'o', 'i', '9595', '9159', 'r', '865', 'l', 'n', 'u', 'u', 'p', 'j']

Answer:
a, i, j, l, n, o, p, r, u, v, x, z