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]: ['n', 'w', '6735', '3427', '6115', 'q', '7851', '3645', 'g', '6825', '6515', '4885', 'z']
[EX A]: g, n, q, w, z

[EX Q]: ['5463', '5683', 'w', '4071', '3997', 'i', '9677', 'q', 'l', 'v', 'w', '5325', '197', 'g', 'g', '3227', '3477']
[EX A]: g, i, l, q, v, w

[EX Q]: ['i', '7419', 'r', 'b', '5291', 'p', '7445', '6823', 'i', 'p', '4261', '9837', '2621', '6799', '3295', '35', '2335', 'w', 'g', 't', '475', '3021', '9991', '5839', 'c', 'q', '117', 'c', 'w', 'g', 'n', 's', 'g', 't', '8827', '5031', '3613']
[EX A]:
b, c, g, i, n, p, q, r, s, t, w