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:
['5293', '2211', 'r', 'j', 'x', 'y', 'u', 'n', 'r', 'l', 'v', '113', 'v', 'e', '1323', '6291', 'a', '7417', 'j', '4175', 'd', '855', 'z', '1123']
answer:
a, d, e, j, l, n, r, u, v, x, y, z


question:
['1649', 'l', 'i', '5901', 'o', 'g', '1197', 'a', '9327', '9835', '1095', 'k', '4489', '9149', 'o', '3095', 'z', 'u', 'y', '561', '7419', 't', 'j', '8763', 'v', '339', 'y', 'w', 'v', 'v', '1867', 'd', 'r', 'w', 'h', 'j', '1531', '3841']
answer:
a, d, g, h, i, j, k, l, o, r, t, u, v, w, y, z


question:
['1403', '5107', 'a', '5457', 'b', '8309', '6245', '5369', 'v', '8319', '8367', 'w', 'k', '885', 'i', 'h', '9233', '5619', 'd', 'c', '4921', '5979', '1895', '191']
answer:

a, b, c, d, h, i, k, v, w