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: ['m', '6443', 'd', 'o', 'p', 'q', '3765', 'k', 'm', 'y', 'j', '3531', 'y', 't', '671', 'j', '3699', 'a', 'i', '1843', 't', 'd', '1205', 'k', 'h', '1209', '2913', '1301', 'k', 'd', '1769', '7985', 's', 'p', 'f', '4583']

Answer: a, d, f, h, i, j, k, m, o, p, q, s, t, y


Question: ['231', 'r', '5673', 'j', '589', 'z', '4659', 'a', '3763']

Answer: a, j, r, z


Question: ['s', 'n', '6627', '7245', '4019', '2363', 'a', '5535', 'i', 'w', '9487', 'o', 'g', '1523', '1177', 't', 'e', 'b', '2505', 'o', 'y', 'e', 'i', '6845', '5289', '579', 'o', 'm', '7729', '2081', '6817', 'm']

Answer:
a, b, e, g, i, m, n, o, s, t, w, y