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: ['9923', 'x', '1901', 'v', '1459', '7503', '3829', '4929', 'k', 'c', '3329', '8793', 'n', 'a', '7249', 'b', 'l', 'l', 'm', 'p', 'b', 'a']

Answer: a, b, c, k, l, m, n, p, v, x


Question: ['2047', '4403', 'g', '3017', '1627', 'v', 'r', '2237', '5513', 'o', 'v', '7229', '9801', 'j', '443', 'z', 'q', 'y', '7447', '1659', '3411', '55', '5153', '9921', '2195', '1075', '8187', 'p', 'x', 'h', 'y', 't', 'a', 'r', 'f']

Answer: a, f, g, h, j, o, p, q, r, t, v, x, y, z


Question: ['459', 't', '7111', 'y', '4663', 'y', '7675', 'r', 'k', '5363', '5291', 'r', 'v', 'd', 'e', 'l', '7183', '6093', 'q', 'a', 'g', 'o', '4873', 'w', 'h', '1803', '5459', 'l']

Answer:
a, d, e, g, h, k, l, o, q, r, t, v, w, y