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

A: d, p, r, t, u
****
Q: ['a', '2579', 'f', '6787', '123', '225', '6499', '4419', 'o', '1785', '7981', 'z', 'b', '2441', '2821', 'o', 'k', '2747', 's', 'u', 'q', '3901', '7629', 'k', 'm', 'q', '6577']

A: a, b, f, k, m, o, q, s, u, z
****
Q: ['d', 'a', 'a', 'x', 'h', 'c', 'k', '1939', 'r', 'y', '1489', '9327', 'm', '2293', 'g', '1167', '1781', 'l', '3479', '5551', '485', 'c', '4453', '7635', 'w', 'x', '9555', 's', 'x', '561', '505', 'n', '1401', 'w', '3235', 'v', 'w', '1225', 'r']

A:
a, c, d, g, h, k, l, m, n, r, s, v, w, x, y
****