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:
['2741', '2541', '8943', 'l', '4047', '2211', 'p', 'e', 't', '7645', '9771', 'f', '5063', '2303', '6097', '5089', 'd', 'e', '1409', '3125', '2171', 'g', '1247', '4045', 'v', 'h', 'u', '2587', '5207', '5553', 'g', 'd', '6891', 'e', '2471', '2435']
answer:
d, e, f, g, h, l, p, t, u, v


question:
['p', 'g', 'q', 'e', '8045', '9999', '9555', '7995', '7195', 'z', 't', '5223', '3699', 'i', '4797', '3817', 'x', 'y', 'w', 'o', '8915', '7803', 'n', '1117', 'c', '9647', 'p', 'e', '9669', '4845', '9255', '4545', '3693', '6871', 'w', '4327', '3285', 'k', 'f', 'x', 'i', 'b', '5967', '6601']
answer:
b, c, e, f, g, i, k, n, o, p, q, t, w, x, y, z


question:
['4659', 'd', 'l', '4471', '9305', '3257', '1415', 'a', 'f', '1271', '797', '7607', '9277', '9637', '1707', 'h', 'b', '3243', '8719', 'x', 'g', '8635', 'j', '9395', '4335', 'j', '9115', 'j', '5241', 'v', 'y', 'h', 'h', 'a', '2851', 's', '7449', 'z', '2055', '3059', '1091', '9269']
answer:

a, b, d, f, g, h, j, l, s, v, x, y, z