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: ['c', '7039', 'g', '1899', 'r', '507', 'c', '2587', '3865', '1729', '3927', 'r', '3535', '2791', 'm', 'l', 'r']

Answer: c, g, l, m, r


Question: ['k', 'j', 'v', '5277', '8607', 'n', '1109', 'e', 'k', '6579', 'o', '2909', 'u', 't', '9685', '8443', '9257', '8071', 'y', 'b', 'h', '4767', 'a', 'j', '8455', 'b', '7733', '2553', 'e']

Answer: a, b, e, h, j, k, n, o, t, u, v, y


Question: ['q', '2163', 'l', '3701', '6487', '5347', 'l', 'w', '5621', 'v', 'g', '6559', 'k', '7119', '4557', '8393', '3683', 'h', '979', '4731', '1227', 'f', '9299', 'j', 'o', 'u', 'j', 'm', 'y', 'e', 'q']

Answer:
e, f, g, h, j, k, l, m, o, q, u, v, w, y