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: ['9117', '1153', 'f', 'b', '9979']

A: b, f
****
Q: ['d', '4377', '9271', '8053', '9519']

A: d
****
Q: ['s', '6885', 'i', 'k', 'i', '3345', 'y', 'd', '9349', 'm', 'd', '8395', 'f', '8365', 'r', 'y', 'j', '3649', '5869', '1635', '159', '3855', 'e']

A:
d, e, f, i, j, k, m, r, s, y
****