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: ['n', 'y', '7087', '9539', 'x', 'i', 'w', '7237', '8613', 'k', '5999', '4179', 'o', 'm', '7485', '1955', 'w', '1451', 'h']

A: h, i, k, m, n, o, w, x, y
****
Q: ['5293', '2211', 'r', 'j', 'x', 'y', 'u', 'n', 'r', 'l', 'v', '113', 'v', 'e', '1323', '6291', 'a', '7417', 'j', '4175', 'd', '855', 'z', '1123']

A: a, d, e, j, l, n, r, u, v, x, y, z
****
Q: ['h', 'r', 't', '6949', '7625', '6499', '953', 'g', 'k', 'u', '533', 'l', 'a', 'z', '5929', 'n', 'z', 'q', '167', '6523', '4229', '9323', '6431', 'g', '6243', 'i']

A:
a, g, h, i, k, l, n, q, r, t, u, z
****