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: ['9117', '1153', 'f', 'b', '9979']

A: b, f
****
Q: ['q', 'o', '1205', '4429', '6301', 'e', '2857', '5075', '5121', 'p', 'b', '5801', 'a', 'm', 'j', 'p', '1279', '7011', 'x', '2557', 'k', 'v', 'b', 'u', 'w', 'n', '1689', 'o', '1583', 'w', '6403', 'p', '6397', 'e', '823', '5699', 'd', '3399', 'd', 'b']

A: a, b, d, e, j, k, m, n, o, p, q, u, v, w, x
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Q: ['3923', 'p', '8557', '3013', '1753', '7045', '6185', '6989', '5725', 't', '493', 's', 'i', '6383', 't', 'r', '1997', 'n', '7609', '1939', 'g', '6489', 'k', 'q', 'w', '8365', '4465', '315']

A:
g, i, k, n, p, q, r, s, t, w
****