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: ['9035', '765', '9359', 'p', '6643', 'd', 'v']

Solution: d, p, v