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:
['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:
['565', 'i', '615', '3047', 'm', '195', '7547', '3003', '9213', '9063', 'c', '5099', 'v', '5003', '9053']
answer:
c, i, m, v


question:
['8395', '2435', 'o', '9339', '4631', '5427', '5259', 'u', '2243', 'i', '8771', 'n', 'o', 'v', '7247', 'n', 'a', '5819', '7903', '4995', 'r', 'b', 'm', '2095']
answer:

a, b, i, m, n, o, r, u, v