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]: ['1985', '729', '169', '1299', 'l', 'z', '6809', '3083', 'w', 'f', '1989', 'z', '889', 'x', 'r', '1601']
[EX A]: f, l, r, w, x, z

[EX Q]: ['749', 'r', 'a', 's', 't', '5905', 'm', 'd', '8437', '4583']
[EX A]: a, d, m, r, s, t

[EX Q]: ['6339', '13', 'x']
[EX A]:
x