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.

[Q]: ['q', '6421', 'w', 'x', '669', 'h', '3853', '6609', 'p', '947', 'g', 'c', 'x', '2617', 'v', 'e', '4795', '5755', 'a', '2379', 'y', '5939', 'l', 'h', 'g', '3779', 'c', 'm', '3157', '4027', 'g', '2917', '9461', '7271', 't', 'i', '9807', '147']
[A]: a, c, e, g, h, i, l, m, p, q, t, v, w, x, y


[Q]: ['u', '1805', 'l', 'l', '5449', 'r', '4471', 'a', 'u', 'c', 'q', '6463', '6717', '7025', '9359', 'q', 'h', '1989', '5497', 'h', 'd', 'c', '135', '5737', '1235', 'v', 'u', 'g', 'p', 't', '9223', '8289', '4489', 'n']
[A]: a, c, d, g, h, l, n, p, q, r, t, u, v


[Q]: ['8127', '67', 'x', 'k', '979', '1339', 'w', 'f', '9117', 'p', '3511', 't', '7803', '5379', 'x', 'r', 'p', 'c', 'c', 'k']
[A]:
c, f, k, p, r, t, w, x