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.

[Q]: ['9351', 'v', 'h', 'z', 'g', 'f', 't', 'q', 'g', 'o', '4073', 'n', '6149', '1735', '157', 'm']
[A]: f, g, h, m, n, o, q, t, v, z


[Q]: ['v', '3765', '4065', 'a', '4201', 'f', 'x', '9275', 'q', '9303']
[A]: a, f, q, v, x


[Q]: ['545', '3079', '355', '1811', '2267', '4315', '5415', 'r', '7015', '365', '9381', '83']
[A]:
r