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: ['s', 'h', 'l', 'w', '7537', '6701', 'n', '9221', 'f', '9555', 'b', '8491', 'x', '765', '8325', 't', '2417', '8563', '2823', 'z', 'r', '6905', '3643', 'q', '1745', '7003', '2501', '8149', 'l', '4889', '3767', '8243', 'h', 'e']
Solution:
b, e, f, h, l, n, q, r, s, t, w, x, z