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: ['r', '4655', 'm', 'l', '4371', 'o', '5331', '5469', 'j', 'u', '4915', 'v', 'i', 'f', 'j', '6139', 'y', '2423', '1271', '2289', '5565', '7561', '9697', 'e', 's', 'u', '9581', 'y', '6095', '5047', '625', '9047', 'd', 's', '8307', '3615', '8145']

Answer: d, e, f, i, j, l, m, o, r, s, u, v, y


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: ['b', 'y', 'p', 't', 's', 'v', '7291', '8315', '2513', 'b', 's', 'w', 'q', 'r', 'y', 'q', 's', '1573', 's', 'i', '6353', '4493', 'k', '1951', 'r', 'n', 'y', 'b', 'e', 'i', 'l', '903', '5337', '6115', 'e', 'c']

Answer:
b, c, e, i, k, l, n, p, q, r, s, t, v, w, y