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: ['5973', 'h', '4081', 'i', '8059', 'w', 'j', '6175', 'w', '8685', '5811', 'k', 'n', '5577', '9817', 'v', '8617', 'u', 'y', '3921', 'b', '1027', '5405', 'a', '3501', '6659', 's', 'e', '157']

Answer: a, b, e, h, i, j, k, n, s, u, v, w, y


Question: ['6027', 'v', 'b', 'l', '7853', 'r', 'y', '2919', '3831']

Answer: b, l, r, v, y


Question: ['6371', 'c', '6327', '3377', '8221', 'k', 'p', '1417', 'f', 'f', '3207', 'x']

Answer:
c, f, k, p, x