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.

[EX Q]: ['m', '8127', '7519', '4543', '2809', '9855', 'n', '6241', 'w', 'w', 'q', 'w', 'p', '8599', '7819', '3817', 'm', 'q']
[EX A]: m, n, p, q, w

[EX Q]: ['5433', '4011', '2113', '2299', 'e', '9829', 'd', 'q', 'e', '3921', 'a', 'q', '8953', 'q', 'g', 'w', 'z', 'u', '4425', 'b', 'q', '5315', 'b', 'u', 'h', 'y', '9733', 'b', 'c', '1225', 'a']
[EX A]: a, b, c, d, e, g, h, q, u, w, y, z

[EX Q]: ['l', 'z', 'k', 'w', 's', '5391', 'a', '1779', 'x', '8679', '5395', '8707', '2465', '2883', 'e', 'q', 'l', 'n', '9159', 'a', '7117', '5459', 'z', 'y', 'n', '159', 'm', '4683', '5027', 'j', 'v', 'm', 'p', 'u', '1623', '9903', 'm', '9735', '5679', 'q', '2983']
[EX A]:
a, e, j, k, l, m, n, p, q, s, u, v, w, x, y, z