instruction:
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.
question:
['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']
answer:
c, d, g, h, j, m, n, p, q, u, v, y, z


question:
['3019', 'g', 'q', 'u', '611', 'z', '3671', '8119', '1679', 'h', '2631', '655', 'k', '2837', 'e', 'f', 'e', 'f']
answer:
e, f, g, h, k, q, u, z


question:
['z', 'b', '373', '9303', '8139', 's', 'c', 'l', 'y', '3243', 'f', '5629', '5867', 'v']
answer:

b, c, f, l, s, v, y, z