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.

['s', 'w', '8949', '4025']
s, w

['7065', 'f', 'k', 'i', 'd', '8291', 'z', 'e', 'q', '5345', 'h', '3397', 's', '5355', 's', '9033', 'e', '5241', '5285', 'm', 'h', 'i', 'n', '6471', '3365', 'f', 'r', '6145', 't', '4869']
d, e, f, h, i, k, m, n, q, r, s, t, z

['u', '4731', '5921', 'r', 'x', '2739', '1767', '9719', '1051', 'v', 's', 'h', '2429', '7737', '6313', 'o', 'd', '1781', '4139', '5067']

d, h, o, r, s, u, v, x