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:
['d', 'p', 'q', '5319', 'w', '4887', '6695', 't', '7711', 'l', '7597', 's', 'n', '1461', 'e', '9045', '1307', 'j']
answer:
d, e, j, l, n, p, q, s, t, w


question:
['v', '6635', '5395', '3263', '4391', 'h', '1521', 'f', '9861', '6125', '1673', '3679', '8681', '4967', 'f', 'a', 'c', 'k', 'n', '4155', 'e', 'm', 'i', '1699', 'r', 'f', 'u', 'r', '3451', 'v', '7239', 'o', '4359', 'l', 'a', '2925']
answer:
a, c, e, f, h, i, k, l, m, n, o, r, u, v


question:
['8065', '9571', '6235', 'y', '6149', 'p', 'a', 'j', 'h', 'f', '2027', '3423', '5087', '2033', 'w', 's', '9737', 'r', 'j', '9589', '807', '191', '6979', 'b', '3241', '9229', 'f', 'v', '6817', '3335', '4123', '6079', '6895']
answer:

a, b, f, h, j, p, r, s, v, w, y