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', 'd', '8153', 'u', '3695', '5317']

A: b, d, u
****
Q: ['8527', 'p', '4697', '8415', 'v', 'l', '2669', '2649', '4349', '4201', 'r', '7573', '2041', 'f', '8047', 'u', 'm', 'm', 'j', '5695']

A: f, j, l, m, p, r, u, v
****
Q: ['4147', '2911', '2145', 'u', 'y', '1641', 'o', 'e', 't', 'b', '137', '8485', 'h', '2637', 'q', '2265', '5149', 'r', '1767', '4085', '1853', 'n', '9187', 'k', 't', '4213', 'l', '8557', 'g', '9277', '9699', 't', '5647', 'b', 's', '3453', 'k', 'm']

A:
b, e, g, h, k, l, m, n, o, q, r, s, t, u, y
****