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:
['4417', 'x', '4641', '885', '8485', 'd', '7057', '8519', 'm', 'i', 'l', '4627', '3069', 'v', '5011', 'u', '6673', 'h', '4541', 'j', '2337', '8175', '4797', 'f', '9109', 'q', 'q']
answer:
d, f, h, i, j, l, m, q, u, v, x


question:
['g', '6867', '7965', '3313', 'k', '1827', '7337', 'u', '1209', '5145', 'w', 'h', '9059', 'u', 'b', '3189', '2837', 'k', 'y', 'e', 'b', '4479', '541', '7103', 'h', 'm', '2177', '6377', '3993', '7167', 'q', '2145', '5007', '9135', '5331', 'e']
answer:
b, e, g, h, k, m, q, u, w, y


question:
['757', 'g', 'u', '2437', '5061', '7773', 'x', '7789', '183', '4553', 'd', '3791', 'z', 'x', 'c', '6385', '2219', 'a', '6417', 'e', '5627', 'r', 'p', 'z', '2543', 'j', '3057', '3991', 'x', 'f']
answer:

a, c, d, e, f, g, j, p, r, u, x, z