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', '1367', '5389', '9515']
[EX A]: w

[EX Q]: ['l', 'o', 's', '7411', '7847', '2557', '1977', '2863', '2325', '4177', '4183', '4241', '1005', '1137', '1371', 'v', 'p', 'a', '2453', 'l', '6315', 'l', '6463', 'n', '7645', '9669', '5411', '1631', '5995', 'z', '227']
[EX A]: a, l, n, o, p, s, v, z

[EX Q]: ['s', '7941', 'x', '6443', 'c', '1123', 'n']
[EX A]:
c, n, s, x