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: ['4009', 'y', '9077', 'p', 'q', '6711', '6443', '5491']

Answer: p, q, y


Question: ['l', '6819', '1029', '2925', '2361', '5545', '2151', '2681', 'f', 'p', '1263', '2875', 'b', '4665', 'f', 'g', 'p', '4829', '8453', 'z', 'l', '4219', '7517', '25', 'a', '5099', '3693', 'i', '1815', '1541', 'g', '7665']

Answer: a, b, f, g, i, l, p, z


Question: ['7313', '9257', '8257', '2339', 'p', 'q', 'c', '4531', 'b', 'g', '829', '9913', 'f', 'j', '1695', 'd', 'r', '39', '8121', '7945', 'k', '181', 's']

Answer:
b, c, d, f, g, j, k, p, q, r, s