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]: ['k', '6595', '1595', 'v', 'h', 'b', '8815', '6681', 'j', '7581', 'p', '9095', '5453', 'r', 'y', '7755', 'x', '1853', 'k', 'q', 'u', 'j', 'q', '9651', 'o']
[EX A]: b, h, j, k, o, p, q, r, u, v, x, y

[EX Q]: ['y', 'i', '257', '3695', 's', '6717', '4817', '4117']
[EX A]: i, s, y

[EX Q]: ['k', 'h', 'b', 't', 'p', '6381', '1717', '4785', '2197', '6467', '1369', '9019', 'b', 'h', 'i', '2579', 'x', 'i', '9403', 'p', '3095', '3287', '5857', '3117']
[EX A]:
b, h, i, k, p, t, x