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: ['2799', '7519', '345', 'e', 'l', '9369', '4703', '4111']

Answer: e, l


Question: ['u', 'k', 'd', '4393', 'u', 'h', 'q', '833', 'k', 'l', '5749', 'r', '7123', '1003', 'z', '531', 'o', 'u', '6601', '6975', '4905', 'n', 'e']

Answer: d, e, h, k, l, n, o, q, r, u, z


Question: ['6397', 'i', '5063', 'j', '4085', 'y', '9141', '5935', '9805', 'm', '9987', 'a', 'u', '2331', 'i', '4825', '353', '2285', 'o', 'v', '4329', 't', '7081', 'j', '7627', 'w', 't', '1543']

Answer:
a, i, j, m, o, t, u, v, w, y