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: ['4905', 'w', '3143', '2217', '573', '1073', '63', 'a', '3971', '2887', '3485', 'y', '3893', '1059', '7623', 'x', 'd', '2991', 'e', 's', '735', 'm', 's', '257', 'x', '5559', '97', 'p', '7237', '693', '7229', 'd', '2311', '807', 'd', 'l', '1247', 'l', '359']

Answer: a, d, e, l, m, p, s, w, x, y


Question: ['2199', 'l', 'o', 'j', 'o', '4521', '5661', 'v', '2517', '6581', '743', 'a', '5437', 'q', 'w', 'q', 'r', '4017', 'q', 'y', 'y', '5177', 'g', 'r', '7893', '3469', 'b', 't']

Answer:
a, b, g, j, l, o, q, r, t, v, w, y