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.

Q: ['9013', 'e', 'm', 'p', 'k', '161', 'k']

A: e, k, m, p
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Q: ['h', 'u', 'y', '7677', '9441', '1769', 'v', '1433', 'l', '7739', 'a', '8305', 'n', 'a', '6711', '3161', 'e', 'u', '993', '2211', '4011', 'q', 'o']

A: a, e, h, l, n, o, q, u, v, y
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Q: ['x', '7417', '4157', '5689', 'e', 'u', '1757', '7765', '4871', '2831', 'b', 'y', 'r']

A:
b, e, r, u, x, y
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