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.

Ex Input:
['8739', 'v', 'm', '6277', 'l', 's', '109', '8057', '3835', 'd', 'u', 'f', 'w', 'd', 'p', '7705', '3643', '4455', 'u', 'p', 'u', '9407', 'g', 'w', '595', 'z', '6827', '6879', 'w', 'w', '6973', 'm', 'e', '1553', 'v', '3529', '8953', '3903', '5713', '8249', 'e', '1113', 'b', 't', 'r']

Ex Output:
b, d, e, f, g, l, m, p, r, s, t, u, v, w, z


Ex Input:
['1707', '381', '3957', '7853', '4987']

Ex Output:
-1


Ex Input:
['3325', 's', 'y', '1633', '9599', 'y', '5175', '6365', '7563', '2039', '8781', '3513', '1773', 'r', '1595', '6135', '2921', 'l', 'g', '985', 'm', '3721', 'z', '9021', '4087', '4923', '8003', 's', '83', '7237', '5385', '6449', '6787', 's', 'w', '7679', '7569', '8845', 'x', '5355', 'g', '5743', '3897', '8229', 'g']

Ex Output:

g, l, m, r, s, w, x, y, z