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:
['r', '4655', 'm', 'l', '4371', 'o', '5331', '5469', 'j', 'u', '4915', 'v', 'i', 'f', 'j', '6139', 'y', '2423', '1271', '2289', '5565', '7561', '9697', 'e', 's', 'u', '9581', 'y', '6095', '5047', '625', '9047', 'd', 's', '8307', '3615', '8145']
answer:
d, e, f, i, j, l, m, o, r, s, u, v, y


question:
['v', 'd', '3805', '8031', '3327', 'c', 'n', '6153', '2705', 'w', '5675', '6543', 'm', 'v', 'y', 'd', '2943', '4423', '515', '4501', 'y', '9377', 'j', 'i', 'f', '4749', 'o', 'r', '2605', 'm', '117', 'o', '9197', 't', 'l', '4145']
answer:
c, d, f, i, j, l, m, n, o, r, t, v, w, y


question:
['i', 'm', 'r', 'x', '4695', '5129', '7573', 'g']
answer:

g, i, m, r, x