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.

['p', '6123', '6961', 't', 'p', 'h', '9035', 'r', '6341', 'x', '3635', '5885', 't', '3543', '9567', '1787', 'o', '2991', 'k', '3441', '4091', 'a', 'r', '423', '9383', '7147', 'h', '663', 'd']
a, d, h, k, o, p, r, t, x

['331', '125', 'u', 'a', 's', '6995', 'i', '3613', '9727', '7087', 'l', 'b', '8291', '813', 'i', '1169', '2159', 'd', '1451', 'q']
a, b, d, i, l, q, s, u

['x', 'n', 'j', '8117', 'l', 'i', 't', '2579', 'c', '3077', '2935', 'a', 'l', '7291', 'f', '7075', 'd', 'o', '3747', '8469', 'p', '9293', '7039', 'r', '5175', 'b', '615', 'n', 'x', '5387', '535']

a, b, c, d, f, i, j, l, n, o, p, r, t, x