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]: ['v', '6635', '5395', '3263', '4391', 'h', '1521', 'f', '9861', '6125', '1673', '3679', '8681', '4967', 'f', 'a', 'c', 'k', 'n', '4155', 'e', 'm', 'i', '1699', 'r', 'f', 'u', 'r', '3451', 'v', '7239', 'o', '4359', 'l', 'a', '2925']
[A]: a, c, e, f, h, i, k, l, m, n, o, r, u, v


[Q]: ['u', 'd', '4193', '5687', 'p', 'r', '7787', 't']
[A]: d, p, r, t, u


[Q]: ['v', '487', 'm', '4257', 'p', '9321', '9551', 'z', 'x', 's', '8249', '6571', 'i', '9501', 'd', '597', '3337', 'i', 't', '259', '2347', 'x', 'q', '8659', '9623', 'g', 'l', '2917', 'r', 'b']
[A]:
b, d, g, i, l, m, p, q, r, s, t, v, x, z