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: ['6575', '2057', '2135', '6259', '7741', '4919', '7461', 'v', '401', 'h', 'u', '2391', '2181', 'y', '9273', 'd', 'b', 's', '7993', '9323', 'b', '7015']

Answer: b, d, h, s, u, v, y


Question: ['j', '1733', 'p', '6741', '7933', '8943', '733', 'x', '1107', 'z', '1719', '7653', 'y', 'z', '6563', 'p', '4615', 'j', '4489', 'h', 'w', 'y', 'p', 'c', '7949', 'k', 'm', 'r', '9427', '7243', '9777', 'j', '323', '4095', 't']

Answer: c, h, j, k, m, p, r, t, w, x, y, z


Question: ['z', '317', '995', '8565', 'w', 'v', '6853', 'j', '5909', 'x', '8769', '4895', '3939', 'o', 'j', '3003', 'e', '5059', 'g', 'g', '3011', 'r', '7285', '493', 'a', 'e', '1789', '7801', '4413', 'l', 't', 'p', 'p', 'f', '5167', '9335', 't', 'u', 't', 'z', 'v', '9405']

Answer:
a, e, f, g, j, l, o, p, r, t, u, v, w, x, z