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: ['t', 'x', '1699', '8727']

Answer: t, x


Question: ['a', 'w', 'm', 'g', 'c', '5475', '7391', 't', '1049', 'p', 'd', '1397', 'k', 'x', 'j', '2525', 'f', '741']

Answer: a, c, d, f, g, j, k, m, p, t, w, x


Question: ['6889', '5479', 'k', 'i', '6911', 'c', '8277', 'i', 'n', 'y', '6011', 'g', 'w', '4983', 'a', '3125', '7865', 'p', '375', 'r', 'k', '7573', '6777', 'l', 'o', 'y', '5419', '7425', '2253', '2707', 'h', 'z']

Answer:
a, c, g, h, i, k, l, n, o, p, r, w, y, z