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: ['2705', 'n', 'r', '8259', '6839', '3239', 'w', 'z', '2611', '2957', '2303', '6315', '7801', 'c', 'w', 'm', '5049', '6465', '599', 'h', 'q', '7559', 'n', '9917', 'v', 'l', '643', '6415', '3587', 'c', '917', '4435', 'p', 'a', '317']

A: a, c, h, l, m, n, p, q, r, v, w, z
****
Q: ['d', '4377', '9271', '8053', '9519']

A: d
****
Q: ['7587', 'r', '7157', '6907', 'z', 'b', '4385', 'n', '287', '7643', '3031', 'n', '7917', 'q', 'y', '3137', 'q', 'w', '8327', '2277', 'l', 'y', 'w', '9117', 'j', '5801', '5787', 'z', 'p', 's', '4373', '1183', '9969']

A:
b, j, l, n, p, q, r, s, w, y, z
****