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]: ['y', 'b', 'r', 'f', '3745', 'n', '2921', '8133', 'r']
[EX A]: b, f, n, r, y

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

[EX Q]: ['1223', '539', '4827', 'd', 'k', 'h', 'g', '1835', '2561', '8785', 'm', '403', '4563', '3957', 'p', 'x', 'v', '6269', 'k', '3291', 't', '4213']
[EX A]:
d, g, h, k, m, p, t, v, x