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: ['9117', '1153', 'f', 'b', '9979']

A: b, f
****
Q: ['3583', 'd', '1481', 'w', 'l', '7261', '2933', 'n', '8725', 'g', '3441', 'r', '287', '7327', '5637', 'r', '5389', 'm', 'j', 'd', 'a', 'e', 'v', '7879', '1731', 'z', '43', 'q', 'p', '4315', 'p', '3651', 'o', 'l', 's', '9787', 'h', '6735']

A: a, d, e, g, h, j, l, m, n, o, p, q, r, s, v, w, z
****
Q: ['7805', '7411', 'p', '889', 'd', '4385', 'c', 'c', '2807', 'r', 'z', 'r', '9495', 'k', 'w', 'f']

A:
c, d, f, k, p, r, w, z
****