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: ['b', 'a', '7411', '4471', 'z', 'l', '2051', 'q', '6749', '8647', 's', 'y', 'h', '9319', 'e', '5419', 'y', 'q']

A: a, b, e, h, l, q, s, y, z
****
Q: ['1627', 'r', '2429', 'b', '4451', 's', 'k', 'm', '269', 'l', '709', 's', 'q', '985', 'x', 'j', 'k', 'k', '6603', 'v', '9497', '477', '5803', 'c', 't', 'f', '3189', '6419', '8561', '5709', 'u', 'z', '5717', '9711', 'w', 'y', 'm', 'v']

A: b, c, f, j, k, l, m, q, r, s, t, u, v, w, x, y, z
****
Q: ['u', 'w', '6437']

A:
u, w
****