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: ['v', 'd', '3805', '8031', '3327', 'c', 'n', '6153', '2705', 'w', '5675', '6543', 'm', 'v', 'y', 'd', '2943', '4423', '515', '4501', 'y', '9377', 'j', 'i', 'f', '4749', 'o', 'r', '2605', 'm', '117', 'o', '9197', 't', 'l', '4145']

Answer: c, d, f, i, j, l, m, n, o, r, t, v, w, y


Question: ['w', '6063', 'i', '261', 'v', '7341', '8003', '3571', 'p', '6183', '7329', 'i', '1567', 'w', '3151', 'j', '2671', '8567', 'q', '8785', 'c', '5837', '7933', 'r', '8225', '2207', '2841', 'p', 'g', '6957', '437', '4035', '8205', 'o']

Answer:
c, g, i, j, o, p, q, r, v, w