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: ['9113', '3625', 'u', '8189', '3649', '259', '5539', '1583', 'g', '4037', 'y', 'v', '8337', 'd', 'q', 'j', 'c', 'h', 'p', '1601', 'z', 'c', 'n', '1767', '1679', '1805', 'm', '4469', '2487', '6015', '973']

A: c, d, g, h, j, m, n, p, q, u, v, y, z
****
Q: ['5011', 'l', '925', 'e', 'b', '3077', 'm', '4541', '781']

A: b, e, l, m
****
Q: ['2137', '4897', 's', '8375', '1073', '6517', 'd', 'u', '281', '2855', 's', '6309', 'v', '6485', 'p', '8377', '645', '6405', 'h', '4561', '1015', '8377', '5275', 'l', 'e', 'g', 'w', '9867', '6907', 'k', 'l', 'w', '3045', '9107', 'a', 'm', 'q', 'r', '5083', 'm', 'b', 'u', 'm']

A:
a, b, d, e, g, h, k, l, m, p, q, r, s, u, v, w
****