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]: ['459', '1729', 'b', 'c', '9619', '4461', '4347', '6733', 'i', '3631', 's', 'j', 'i', 'r', '5293', 'q', '7397', '4309', 'c', 'n', 'k', '197', 'q', '8139']
[EX A]: b, c, i, j, k, n, q, r, s

[EX Q]: ['q', '6421', 'w', 'x', '669', 'h', '3853', '6609', 'p', '947', 'g', 'c', 'x', '2617', 'v', 'e', '4795', '5755', 'a', '2379', 'y', '5939', 'l', 'h', 'g', '3779', 'c', 'm', '3157', '4027', 'g', '2917', '9461', '7271', 't', 'i', '9807', '147']
[EX A]: a, c, e, g, h, i, l, m, p, q, t, v, w, x, y

[EX Q]: ['7443', 'a', '9309', '6349', '8387', 'y', 's', 'i', 'l', '241', '4199', 's', '5549', '4431', '117', '2443', '1601', '4713', '7871', '2717', 'm', '6227', 'f', '1467', 'y', '963', 'r', '6063', 'a', 'y', '9135', 'e', '1773', '8505', '8763', '3575', '1097', '3929', '4389', 'g', '7489', '7923']
[EX A]:
a, e, f, g, i, l, m, r, s, y