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: ['7777', '6223', 'k', 'k', 'd', '9743', '189', '7705', 'c', '6115', '4275']

Answer: c, d, k


Question: ['8281', '4831', '1329', 'g', 'e', '8879', 'n', 's', 'x', 'j', '6305', 'j', '921', '3677', '5107', 'n', 'j', '9285', 'a', '5329', '6671', 'c', '9283', 'l', 'a', '7907', 'q', '7605', '855', '6477']

Answer: a, c, e, g, j, l, n, q, s, x


Question: ['q', '3891', 'd', 'n', 't', 'c', 't', '3933', '893', '1435', 'v', '325', '313', '4541', '2319', '2567', '3583', '495', '3745', '3489', '4019', 'h', 'k', '2907', '7397', 'p', '5697', '8701', 's', '9857', 'n']

Answer:
c, d, h, k, n, p, q, s, t, v