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:
['7109', '1243', 'f', 'z', 'h', 'd', '6169', 'v', 'h', '3609', '3181', 'd', '3661', '7193', '7341', '9127', 'r', '1623', '5813', 's', 'd', '4011', '4983', 'n', '4195']
answer:
d, f, h, n, r, s, v, 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:
['f', 'z', 'm', '9523', '751', 'h', 'g', 'd', 'j', 'b', 'o']
answer:

b, d, f, g, h, j, m, o, z