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:
['5785', 'c', 'f', '7087', 'd', '9225', 'm', 'g', '4639', '7165', '3445', '3813', 'p', 'i', '719', 's', 'g', '6423', '9563', 'w', 'm', '8659', '8809', '4105', '3923', '465', '5637', '5547', 'h', 'v', '9453', '4009']
answer:
c, d, f, g, h, i, m, p, s, v, w


question:
['i', 'y', '8339', 'd', 'b', '7471', '6577', '9037', '4503', '6287', '1439', '8863', '9201', '2661', 'x', 'l', 'v', 'w', 'a', 'f', '8885', '519', '7631', 'g', '7203', '8605', '2429', '9165']
answer:
a, b, d, f, g, i, l, v, w, x, y


question:
['f', 'o']
answer:

f, o