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:
['q', '8149', '4087', '5183', 't', 'j', 'e', 'g', 'r', '2125', 'y', 'l', 'g', '3673', 's', 'r', 'e', 'v', '4259', 'v', '3477', '9353', '3639', 'v', 'n', 'e', 'z', '5071', 'x', '6287', 'e', 'e']
answer:
e, g, j, l, n, q, r, s, t, v, x, y, z


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:
['b', '8863', 'r', 'g', '1849', '385', '3053', 'v', '9549', '811', '923', 'p', '5709']
answer:

b, g, p, r, v