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: ['t', 'u', 'y', 'y', 'b', 'x', 'q', '3713', '2679']

A: b, q, t, u, x, y
****
Q: ['t', 'h', '6141', 'g', 'f', 'z', 'n', 'b', 'k', '9059', 'y', 'p', '4289', '2683', 'a', '3267', 'w', 'p', 't', '3623', '7759', 'a', 'o', 'm', '9815', 'q', 'u', '8051', '6871']

A: a, b, f, g, h, k, m, n, o, p, q, t, u, w, y, z
****
Q: ['d', '3073', 's', '6837', 'w', 'y', 'v', '5959', '7275', '1681', 'r', '8217', 'z']

A:
d, r, s, v, w, y, z
****