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: ['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: ['p', 'p', '7899', 'u', '971', '7289', 't', '5217', 'k', 'z', 'y', 'y', '6905', '9499', '4085', 'x', '955', 'v', 'j', '9049', '7927', '1757', '193', '2181']

A: j, k, p, t, u, v, x, y, z
****
Q: ['d', 'y', '3285', '5499', 'q', 'j', 'k', '3721', 'a', '9485', 'r', 'f', 'a', 'a', '5267', 'l', 'q', '9305', '5693']

A:
a, d, f, j, k, l, q, r, y
****