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', '771', '4193', 'e', '1537', 'a', 'q']

A: a, d, e, q
****
Q: ['b', 'd', '8153', 'u', '3695', '5317']

A: b, d, u
****
Q: ['6493', 'x', '4865', '2703', '7805', '8589', 'q']

A:
q, x
****