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: ['1063', 'f', 'm', 'i', 'x', 'i', 'd']

Answer: d, f, i, m, x


Question: ['2293', 'p', '9787', '7241', '8689', 'u', '3141', 'h', 'c', 'b', 'f', 's', '319', 'c', 'p', '6909', 'p', 'f', '1717', 'd', '2285', 's']

Answer: b, c, d, f, h, p, s, u


Question: ['d', 'x', 's', 'i', '5299', 'a', '2129', 't', '2933', '2105', 'u', 'j', 'g', 'k', 'r', '7133', '2985', '2831', '6395', 'y', 'q', '9513', '4161', 'x', 'b', 'a', '6827']

Answer:
a, b, d, g, i, j, k, q, r, s, t, u, x, y