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: ['2697', 's', '8733', 'n', '5871', 'f']

A: f, n, s
****
Q: ['9273', '5219', 'e', '9413', 'v', 'h', '5657', '797', '2303', '2119', '4791', '2757', '4983', 'h', '9681', '4503', '6657', 't', 'i', 'g', '9375', '9901', 'm', 'y', '6461', 'h', '6663', '9493', '5897', '8829', 'd', 'x', '901', '833', 'u']

A: d, e, g, h, i, m, t, u, v, x, y
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Q: ['9947', '2791', 'c', '1989', '6989', 'q', '8887', 'p', 'w', 'm', '8203']

A:
c, m, p, q, w
****