Q: 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.
['2987', '7593', '8385', '993', 'y', 'g', 'f', 'm', 'm', 'l']
A:
f, g, l, m, y