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: ['5159', '6407', '4021', '6655', 'c', 'k', 'w', '7191', 'l', '4321', '1609', 'm', '1991', '9261', '511', 'p', '7495', 'b', 'e', '4647', '2711', 'd', 'y', '3835', '5037', '3613', '2695', '3367', 'm', 'j', 'y', '9561', '4889', 'a', 'z', '2253', 'p', 't', 's', '8371', '2859', 's']

Answer: a, b, c, d, e, j, k, l, m, p, s, t, w, y, z


Question: ['1189', '7143', '993', '1513', '6449', '9749', '5963', '8159', 't', '3543', 'j', 'i', '4227', '1463', '6431', '4987', 'y', 'q', 'f', '321', 'm', 'r']

Answer: f, i, j, m, q, r, t, y


Question: ['w', '9031', '3641', '5525', '5379', 'f', 'm', '4767', 'p', 'e', 'k', 'k', 'p', 'i', '3489', '8605', '7403', '4945', '5559', '8625', '7523', 'x', '3461', '5517', 'd', '3077', 'h', '5033', 'e', 'o', '6055', '2059', 'p', 'f', 'f', 'j', 'z', '4269', '6491', '1973', '787', '4033', 'y']

Answer:
d, e, f, h, i, j, k, m, o, p, w, x, y, z