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: ['s', 's', '3619', '6051', 'h', '213', '3937', 'v', 'p', 'y', '8449', '9337', '5327', 'a', 'a', 'w', '3985', 'n', 'm']

Answer: a, h, m, n, p, s, v, w, y


Question: ['5433', '4011', '2113', '2299', 'e', '9829', 'd', 'q', 'e', '3921', 'a', 'q', '8953', 'q', 'g', 'w', 'z', 'u', '4425', 'b', 'q', '5315', 'b', 'u', 'h', 'y', '9733', 'b', 'c', '1225', 'a']

Answer: a, b, c, d, e, g, h, q, u, w, y, z


Question: ['r', '3931', 'm', '6929', '1991', '363', 'z', '9727', '5569', '4333', '3125', '8729', '9919', '6665', 'v', 'u', 'x', '5801', 'r', 't', 'n', 's', '7575', 'c', 'j', '4089', 'l', 'x', 'i', 'k', '4435', '7305', '7935', 'b', 'f']

Answer:
b, c, f, i, j, k, l, m, n, r, s, t, u, v, x, z