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', 'q', '6461', 's', '8565', '2237', '2071', '8143', '2977', '5511', 'j', 'o', '5793', 'j', 'm', 'n', '8031', 'j', '535', '5001', 's', 'y', '1737']

Answer: j, m, n, o, q, s, y


Question: ['7155', 'y', '145', '7147', 'u', '8453', 'd', '3693', '6471', '5289', 'n', 'p', '8289', '2929', '199', 'e', '8377', '8937', '5315', 't', 'l', '7715', 'c', 'y', 'f', '9999', 'p', '3655', '5489', 'q', '2321', '9881', '2265', 'n', 'v', '455']

Answer: c, d, e, f, l, n, p, q, t, u, v, y


Question: ['8917', '5687', 'n', 'i', '1673', '7105', 'f', 'x', '8097', 'z', 'y', '8631', 'y', '3663', 's', '7449', '1679', 'l', 'h', 'x', 'z', '3', 'i', '5521', '9373', '7907', '629', '1137', 'f', 'y', 'h', 'i', '6257', '9895', 'l', 's', '4449', 'p', 'e', 'm', '4487', 'c', '8653', 'b']

Answer:
b, c, e, f, h, i, l, m, n, p, s, x, y, z