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: ['315', '9975', '3013', 's', '6131', 'e', 'e', 'u', 'a', '1729', 'g', 't', 'y', 'f', '7523', 'e', 'g', '489', 'm', 'p', 'f', 'e', '2077', 'e', 'g', 'c', 'l', '6389', 'k', 'b']

A: a, b, c, e, f, g, k, l, m, p, s, t, u, y
****
Q: ['f', '9203', 'w', 'f', '3751', '8095', '1319', 'f', '3017', 'r', 'y', '8221', '2715', '9959']

A: f, r, w, y
****
Q: ['d', '6665', '8681', 'r', 'u', '7335', '869', 'd', 'z', '1829', 'l', '2977', 'm', 'k', '3197', '8047', 't', '3717', 'x', '9997', 'f', '3889', 'p', '4265', 'v', 't']

A:
d, f, k, l, m, p, r, t, u, v, x, z
****