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]: ['9403', '9881', '8391', 't', '1793', 'w', 'x', 'y', '6383', 'j', 'r', '5323', 'r', 'l', 'e', 'u', '7193', '2309', '837', 'z', 'w', 'n', '4427', '8269', '6333', 'a', 'p', '1933', '8497', '2665', '1349', '6807', '9009', 'b']
[EX A]: a, b, e, j, l, n, p, r, t, u, w, x, y, z

[EX Q]: ['8821', '9833', 'l']
[EX A]: l

[EX Q]: ['8417', '5647', '799', 'g', '7661', 's', '5183', '2473', 'c', '1073', 'w', '2833', 'v', '707', '5887', '7213', 'm', 'v', 'b', 'l', 'o', '3855', 'l', 'e', '1447', '1121', 'j', 'd', '9257', 'c', '6045', '8539', '4977', 'w', '5481', '5603', '523', '6965', '8143', 'x']
[EX A]:
b, c, d, e, g, j, l, m, o, s, v, w, x