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: ['i', '639', 'x', '5545', 'n', 'x', '8859', 't', '845', '4243', '5727', '8463', 'g', '6011', 'g', '1281', 'f', '2025', 'j', '9975', 'c', 'n', 'l']
A:
c, f, g, i, j, l, n, t, x