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: ['1447', 'q', '9529', '2971', 's', '7351', '6753', '3493', 'v', 'c', 'x', '3097', '9145', 'b', 'e', 'b', '2967', '6933', 'e', 's', 'v', 'f', 'z', 'r']

Answer: b, c, e, f, q, r, s, v, x, z


Question: ['p', '9641', '8515', '1207', 'd', 'j', '6617', '5529', 'g', 'a', 'o', 'f', 'y', '4993', '4643', '6087', 'n', '3177', 'y', '9471', '1229', '8211', '7079']

Answer: a, d, f, g, j, n, o, p, y


Question: ['9585', 't', '8691', 'e', 'm', '301', 'i', 'r', 'z', '9897', '4289', '9751', 'k', '4377', '6345', '2579', 'q', 'g', '7453', '811', '8753', 'e', '5051', 'm', 'r', '8527', '6969', '9725']

Answer:
e, g, i, k, m, q, r, t, z