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: ['w', '743', '5757', '8731', 'k', 'p', '317', 'n', 'x', '5649', 'l', 'm', 'c', '2499', 'l']

Answer: c, k, l, m, n, p, w, x


Question: ['g', 'p', '2925', 'n', 'o', 'y', '6381', 'l', '4963', 'g', 'm', 'u', 't', '9389', '3787', '7713', '1251', '779', 'i', 'w', '9869', 'y', 'y', '3881', 'k', 't']

Answer: g, i, k, l, m, n, o, p, t, u, w, y


Question: ['q', 'h', 'h', '1379', 'b', '3327', 'i', 't', '9157', 'l', '8621', 'y', 'p', '7401', 'e', '8481', 's', '7135', '8889', '1893', 'u', 'y', 'a', '3165', '6777', '9885', '9683', 'c', '6329', 't', '9009', 'k', '5509', '8119', '1643', 's', '3903', 'f', '8355', 'l', '5813', '5839', 's', 'a', 'c']

Answer:
a, b, c, e, f, h, i, k, l, p, q, s, t, u, y