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: ['k', 'r', 'f', '4369', 'z', 'z', 'l', '143', 'r', '707', '9167', 'g', '1749', 'i']

A: f, g, i, k, l, r, z
****
Q: ['m', '3809', 'l', 'k', '1929', '7963', 'n', 'u', '2125', 'g', 'o', '8325', 'o', 'h', 'y', '3025', 'e', 'e', 'c', 'x', '8445', '4979', 'z', 'f', '4201', '4765', 'g']

A: c, e, f, g, h, k, l, m, n, o, u, x, y, z
****
Q: ['u', 'b', '609', '6883', '2541', '5039', 't', 'c', 'x', '6417', '2401', 'q', 'u', 'r']

A:
b, c, q, r, t, u, x
****