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]: ['w', '743', '5757', '8731', 'k', 'p', '317', 'n', 'x', '5649', 'l', 'm', 'c', '2499', 'l']
[EX A]: c, k, l, m, n, p, w, x

[EX Q]: ['6495', '2259', '8213', 'm', 'y', '3377', 'q', 'i', '1299', 's', 'w', '4331', 'h', '5459', '4059', '6637', '8069', '5367', '6025', 'l', 'v', '4503', 'd', 'x', 'w', '5067', '9019', 'd', '7919', '7299', 'v', '8957', 'v', '5341', '2617', '8169', 'n', 'y']
[EX A]: d, h, i, l, m, n, q, s, v, w, x, y

[EX Q]: ['t', '4379', '4591', 'm', 's', '3761', '5497', '327', '2835', 'm', '2491', '3049', '8483', '1739', '5301', 'h', '3761', 'f', 'k', '6171', 'm', '9393', '799', 'p', 'o', '9637', '5289', 't', 'v', 'm', '8537', 'c', '6233', '4545', 'l', '3845', 'x', 'f', '7671', 'n', '4343', 'b', 'k', 'n', '245']
[EX A]:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
b, c, f, h, k, l, m, n, o, p, s, t, v, x

