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.
Example: ['8129', 'a', '4245', 'y', 'm', 'a']
Example solution: a, m, y
Example explanation: Here, the unique alphabets in the list are 'a', 'y', and 'm', hence their sorted order is 'a, m, y'.

Problem: ['4341', '8809', '7337', 'h', '2857', '4965', '7283', 'x', '2197', 'd', '2711', '9791', '6771', '287', 'i', 'k', '1313', '9583', '515', 'v', '4855', 'p', 'y', 'r', '4837', 'u', 'z', '6477', 'j', 'j', '303', 'y', '7355', '3447', 'q', 'y', '5999', '1537']

Solution: d, h, i, j, k, p, q, r, u, v, x, y, z