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: ['7911', '7175', 'y', '9173', 'y', '2529', '831', 'k', '7197', 'j', '2343', 'i', 'b', '6799', '5987', '7277', 'n', 'x', 'h', '7209', 'l', 'd', 'm', 'e', '2277', '8909', 'x', '5361']

A: b, d, e, h, i, j, k, l, m, n, x, y
****
Q: ['x', 'i', 'r', '6011', 't', 'f', 'b', 'i', '8367', '4051', '1459', 'f', '5583', '9609', 'l', 'q', 'g', '8443', 'o', '8697', '7053', '8325', 'k', '7021', 'q', 'm', '6899', '9981', '8985', 'i', 'j', '8043', 'k', '535', '7603', '7629', 'k', '2779', 'g', '2049', 'x', 'd', '8527', 'k', 'q']

A: b, d, f, g, i, j, k, l, m, o, q, r, t, x
****
Q: ['a', 'c', '3769']

A:
a, c
****