Q: 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.
['e', '9193', '8733', '1949', '2649', 'h', '3863', '757', 'w', 'x', 'o', 'u', '5575', 'i', 'g', 'u', '5177', 'b', 'l', '2693', 'c', '9751', '6469', '2887', 'e', 'r', 't', '9391', 'f', '2859', '6609', '4451', 'r', 'h', 'q', 'g', 'l', 'j', 'r', '4883', '8609', '3299', '3699', 'o', 'd']
A:
b, c, d, e, f, g, h, i, j, l, o, q, r, t, u, w, x