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.

[EX Q]: ['2293', 'p', '9787', '7241', '8689', 'u', '3141', 'h', 'c', 'b', 'f', 's', '319', 'c', 'p', '6909', 'p', 'f', '1717', 'd', '2285', 's']
[EX A]: b, c, d, f, h, p, s, u

[EX Q]: ['2995', '8179', '8131', '5655', 'j', 'q', 'l', '3193', '1823', 'y', 'n', '7645', 's', '5665', 'r']
[EX A]: j, l, n, q, r, s, y

[EX Q]: ['l', 'u', 'z', '7987', 'y', 'm', 'm', '765', '3479', '4707', '8101', '7115', 'k', 'e', '193', '6629', 'u', '6437', 'v', '2665', '7149', 'd', 'e']
[EX A]:
d, e, k, l, m, u, v, y, z