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: ['8311', 'w', 'f', '3431', '9863', '5817', '3969', '2705', 'x', 'm', 'k', 'z', 'z', '235', 'x', '417', 's', 'i', 'y', '8833', '8675', 's', 'm', '2149', '765', 'u', '1021', '7823', 'x', '7275', '3157', 'k']

Answer: f, i, k, m, s, u, w, x, y, z


Question: ['w', '1081', 'n', '2073', 't', '6351', '5591', 'a', '113', 'w', 'q']

Answer: a, n, q, t, w


Question: ['4363', 'c', '9245', 'w', 'm', '1823', '3413', 'q', '5145', 'a', '8037', '6791', '4297', '7265', '5069']

Answer:
a, c, m, q, w