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]: ['s', 'w', '8949', '4025']
[EX A]: s, w

[EX Q]: ['t', 'a', '2481', '2841', 'a', '2871', 'm', '4435', 'g', '8201', '4351', '9045', 'o']
[EX A]: a, g, m, o, t

[EX Q]: ['w', '7485', '5125', '3483', 't', 'q', 'k', '1205', 'm']
[EX A]:
k, m, q, t, w