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]: ['2161', '8009', '3057', 'r', '3897', 'd', 'j', '2727', 'b', '3231', 'i', '9227', '393', '5799']
[EX A]: b, d, i, j, r

[EX Q]: ['6027', 'v', 'b', 'l', '7853', 'r', 'y', '2919', '3831']
[EX A]: b, l, r, v, y

[EX Q]: ['x', 'd', '863', '9767', 'z', 'w', '6373', 's', '5039', 'a', '6929', '9531', '2295', 'c', '6915', 'v', '5851', '8037']
[EX A]:
a, c, d, s, v, w, x, z