Detailed Instructions: 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: ['d', 'v', '1829', '4047', '4971', 'r', '6535', 'r', '3673', '5501', 'p', 'y', 'g', '2843', 'z', 'd', '4051', '2999', '1765', 'k', '5277', '4191', 'l', '7455']
A:
d, g, k, l, p, r, v, y, z