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: ['u', '9249', 'u', 't', 'm', 'm', 'n', 'w', '8617', '2729', 'i', 'l', '2971', '3227', 'b', '9017', '4711', 'i', 't', 'r', 'a', 'a', '1701', '6397', '4535', '9167', '6039', '6111', '849', 'p', '8197', '2645', '5147', 'u', 'l', '7419', 'w', 'w', 'k', 'x', 'c', '3377', '4015', '1297', 'f']

Answer: a, b, c, f, i, k, l, m, n, p, r, t, u, w, x


Question: ['2313', '2073', 'd', 'e', 'o', '793', '4999', 'f', 'c', '4473', '4519', 'u', 'n', 'k', '69', '475', 'a', 'j', 'q', 'x', '5869', '9523', 'z', 'v', '9265', '5989', 'p', 'm', 'g', 'y', 'b']

Answer: a, b, c, d, e, f, g, j, k, m, n, o, p, q, u, v, x, y, z


Question: ['4495', 'd', '635', '2155', '6407', '4029', '8235', 'x', '4417', 'x', 'd', 'r', 'z', 'q', '4715', 'w', 'g', '2405', 't', 'h', 'x', 'n', 'u', 'h']

Answer:
d, g, h, n, q, r, t, u, w, x, z