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]: ['t', 'x', '1699', '8727']
[A]: t, x


[Q]: ['y', '8115', 'f', '5333', 'f', '3437', 'b', 'e', '5719', 'm', 'w', '95', '4863', 'k', '4895', 'a', '8179', 'm', '7919', '1731', '229', 'r', '1847', '7559', '6669']
[A]: a, b, e, f, k, m, r, w, y


[Q]: ['m', '8127', '7519', '4543', '2809', '9855', 'n', '6241', 'w', 'w', 'q', 'w', 'p', '8599', '7819', '3817', 'm', 'q']
[A]:
m, n, p, q, w