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]: ['5957', 'd', 'i', 'b', 'e', '5565', 'c', 'i', '2919']
[EX A]: b, c, d, e, i

[EX Q]: ['4213', '3595', '7937', 'y', '5723', 'v', 'b', '7007']
[EX A]: b, v, y

[EX Q]: ['x', '9721', 'd', 's', '5847', 'e', '571', '6851', 'p', '3125', '9961', 'r', 'o', 'f', '6525']
[EX A]:
d, e, f, o, p, r, s, x