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: ['s', 's', '3619', '6051', 'h', '213', '3937', 'v', 'p', 'y', '8449', '9337', '5327', 'a', 'a', 'w', '3985', 'n', 'm']

A: a, h, m, n, p, s, v, w, y
****
Q: ['277', '8697', 'q', '2023', '5723', 'm', '8673', 'f', 'z', 'z', 'a', '9875', 'p', 'x', 'l', 'z', 'x', '619', '6509', 's', '2067', '571', 't']

A: a, f, l, m, p, q, s, t, x, z
****
Q: ['m', '8859', 'l', 'y', 'a', 'b', 'p', 'j', 'x', 'o', '2189', '4909', '4735', 'u', '1489', '7043', 'x', 'n', '2353', 'q', '6277', 'g', '6047']

A:
a, b, g, j, l, m, n, o, p, q, u, x, y
****