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: ['5499', 'm', '327', 'h', '5765', '4231', 'y', 'g', 's', '883', '9843', '2751', '8967', 'z', '2301', 'l', 'l', 'k', '7843', '7221', '3643', 'k', '5951', 'r', '9441', '235', '3835', 'l', 'e', 'y', '4061', 'l', '1177']

Answer: e, g, h, k, l, m, r, s, y, z


Question: ['8821', '9833', 'l']

Answer: l


Question: ['m', 'x', '1973', '2153', '1167', 'v', '6299', 'o', '9079', 'd', '8985', 'm', 'c', '6797', 'z', '5957', '3895', 'k', 'k', '9383', '1581', '4817', 't', '8217', 'w', 'b', 'v', '6187', 'x', '4557', '793', 's', '3587']

Answer:
b, c, d, k, m, o, s, t, v, w, x, z