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.

['9579', 'm', 'v', 'r']
m, r, v

['q', '8149', '4087', '5183', 't', 'j', 'e', 'g', 'r', '2125', 'y', 'l', 'g', '3673', 's', 'r', 'e', 'v', '4259', 'v', '3477', '9353', '3639', 'v', 'n', 'e', 'z', '5071', 'x', '6287', 'e', 'e']
e, g, j, l, n, q, r, s, t, v, x, y, z

['k', '1363', 'm', 'd', '4645', 'f', 's', '9827', '9943', '4259', '495', '2045', 'u', '1797', '1079', 'p', 'j', '5181', 'w', '4949', '8195', 'u', '6491']

d, f, j, k, m, p, s, u, w