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.
One example: ['8129', 'a', '4245', 'y', 'm', 'a']
Solution is here: a, m, y
Explanation: Here, the unique alphabets in the list are 'a', 'y', and 'm', hence their sorted order is 'a, m, y'.

Now, solve this: ['k', 'q', 'y', 'c', 'w', 't', '2637', '5069', '7789', 'u', 'c', 'n', '4349', 'c', 'o', '7397', '1837', 'r', '449', '7955', '8871', 'e', '427', 'b', '5249', '3055', 'i', 'v', 'v', '3861', '2143', '2623', '9591', '4367', 'i', '7545', 'd', 'a', '2595', '6895']
Solution:
a, b, c, d, e, i, k, n, o, q, r, t, u, v, w, y