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: ['7917', '2295', 'q', 'v', '9373', 'w', 'n', 'q', '5803', 'g', 'k', 'm', '2167', 'k', '6425', 'x', 'g', '341', 't', 'u', '8829', 'h', '4333']

A: g, h, k, m, n, q, t, u, v, w, x
****
Q: ['t', 'x', '1699', '8727']

A: t, x
****
Q: ['s', '4583', 'n', '7593', 'b', '6235', '8995', 'n', '6951', '8917', '1889', '8979']

A:
b, n, s
****