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: ['n', '9571', '2983', '7597', 'v', 'y', '1993', '1403', '8309', '7043', 'c', '7329', 'p', '4479', 'p']

Answer: c, n, p, v, y


Question: ['w', 'i', '4383', '7667', '9617', 'y', 'a', '8051', 'w', '4857', 'y', '3953', 'u', 'o', 'y', 'i', '9201', 'g', '1807', '5367', 'g', '5263', '3995', '6665', '3113', '9433', '6315', 'm', '845', 'x', 'c', 'v', 'h', '1491', 'g', '3519', 'x', 'b', '7695']

Answer: a, b, c, g, h, i, m, o, u, v, w, x, y


Question: ['a', '8359', 'g', '6493', 'r', '7279', 'q', '4737', '6949', 'm', 'z', '1951', '4667', 'n', '2833', 'f', 'j', 'i', 'v', '5759', 't', '5727', '2817', '4573', 'c', 'g']

Answer:
a, c, f, g, i, j, m, n, q, r, t, v, z