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:
['7065', 'f', 'k', 'i', 'd', '8291', 'z', 'e', 'q', '5345', 'h', '3397', 's', '5355', 's', '9033', 'e', '5241', '5285', 'm', 'h', 'i', 'n', '6471', '3365', 'f', 'r', '6145', 't', '4869']
answer:
d, e, f, h, i, k, m, n, q, r, s, t, z


question:
['o', '5503', '5837', '4539', '7631', 'm', '2641', 'p', '7901', '8117', 'z', '3373', '3215', 'v', 'a', '5949', 'w', '9049', 'd', 'a', 'l', 'v', 'l', 'n', 'w', 'r', 'j', '9031', '9609', '4209', 'c', '7453', '5855', '2883', '5941', 't', '4283', 'x', 'x', 'n', 'c']
answer:
a, c, d, j, l, m, n, o, p, r, t, v, w, x, z


question:
['c', '8987', '9479', '2067', '2921', '8637', 'd', 'l', '9953', '2205', '4787', '8017', 'k', '5453', '2563', '9469', 'd', '3631', '2985', '7583', '831', 'o', 's', '2191', 'r', 's', '4759', '3205', '9483']
answer:

c, d, k, l, o, r, s