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:
['1593', '8165', 'q', '6689', 'b', 'r', '373', 'g', '6505', '415', '495', 'j', 'j', 'f']
answer:
b, f, g, j, q, r


question:
['m', '7517', '9361', '9567', '8785', 'k', '5699', '3585', 'v', '1913', '1651', 'g', 'p', '2731', 'q', 'h', '467', 'r', '1091', '9801', 'a', '6645']
answer:
a, g, h, k, m, p, q, r, v


question:
['5685', 't', 'a', '2231', 'g', 'a', 'm', 'o', '289', '1301', 'd', 'n', '489', 'k', 'i', '5173', 'e', '9245', 'w']
answer:

a, d, e, g, i, k, m, n, o, t, w