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: ['459', '1729', 'b', 'c', '9619', '4461', '4347', '6733', 'i', '3631', 's', 'j', 'i', 'r', '5293', 'q', '7397', '4309', 'c', 'n', 'k', '197', 'q', '8139']

A: b, c, i, j, k, n, q, r, s
****
Q: ['6175', '9441', '7127', '5979', 's', '1367', 'e', 'm', '7083', '1787', '8375', '2851', '3475', 'r', '697', 'g', 'z', 'm', '4207', 'c', '7971', 'z', '9339', 'd', 's', '3507', '9003', 'i', 'y', 'w', 'j', 'i']

A: c, d, e, g, i, j, m, r, s, w, y, z
****
Q: ['q', 'v', 'r', '5967', '2877', 'f', '3407', 'e', '4593', 'k', '2831', '3257', 'k', 't', 'j', 'f', '3947', '7513', 'y', 'g']

A:
e, f, g, j, k, q, r, t, v, y
****