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.

['l', '6819', '1029', '2925', '2361', '5545', '2151', '2681', 'f', 'p', '1263', '2875', 'b', '4665', 'f', 'g', 'p', '4829', '8453', 'z', 'l', '4219', '7517', '25', 'a', '5099', '3693', 'i', '1815', '1541', 'g', '7665']
a, b, f, g, i, l, p, z

['j', '1733', 'p', '6741', '7933', '8943', '733', 'x', '1107', 'z', '1719', '7653', 'y', 'z', '6563', 'p', '4615', 'j', '4489', 'h', 'w', 'y', 'p', 'c', '7949', 'k', 'm', 'r', '9427', '7243', '9777', 'j', '323', '4095', 't']
c, h, j, k, m, p, r, t, w, x, y, z

['2441', '4537', 'n', 'k', 'j', 'g', '5053', 'o', '9669', '25', 'd', 'b', 'e', 'y', 'g', 'k', 'i', '545', '2745', 'z', 'w', 'j', 'f', '7103', '6801', 'i', 'y', '9139', '625', '3527', 'n']

b, d, e, f, g, i, j, k, n, o, w, y, z