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: ['l', 'u', '3901', '341', '5801']

A: l, u
****
Q: ['d', '4377', '9271', '8053', '9519']

A: d
****
Q: ['a', 'p', 'y', 'l', 'l']

A:
a, l, p, y
****