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:
['9425', 'l', 'c', 'n', '5925', '2543', '3935', 'c', '7533', 'j', 'q', '3775', '5897', '9435', '69', 'e']
answer:
c, e, j, l, n, q


question:
['b', 't', '2199', 'e', 'i', '1883', '5137', '8495', 't', '7377', 'm', '7665', '2009', 'o', '3757', 'm', '861', 'm', 'l', '9229', 'c', 'r', 'q', 'i', 'm', '705', 'b', '4301', 'd', 'l', 'f', '5485', 'h', 'p', '4529', '7879', 'f', 'b', 'm']
answer:
b, c, d, e, f, h, i, l, m, o, p, q, r, t


question:
['229', '8267', 'v', '9041', 'p', '4489', 'x', '2461', '9371', 'w', '5635', '4635', '8567', 'u']
answer:

p, u, v, w, x