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:
['o', '1217', '449', 'n', 'e', 'o', 't', '9043', '1925', '5687', '7197', '7943', 'u', '5053', 'q', 'e', '89', 'l', 'h', '3083', '4295', 'o', 'n', '6309', '743', 'n', 'j', '2105', 's', '6845', 'p', 'p', '1355', '3757', 'v', 'f', '961', '4623', '4633', 'p', '4593', 'p', '7337', 'o', 'u']
answer:
e, f, h, j, l, n, o, p, q, s, t, u, v


question:
['7997', 'm']
answer:
m


question:
['g', 'l', 'f', '3373', 'h', 'o', 'c', '7223', '5303', '6649', '3449', 'd', 'm', 'w', '4351', 'd', 'c', '9487', '195', 'd', '1833', 's', 'f', '7399', '4395']
answer:

c, d, f, g, h, l, m, o, s, w