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.
['2021', 'k', '169', '4283', 'x', 'c', 'r', 'v', '897', '1675', '3761', '8875', '7723', 'v', '3525', 'v', 'd', '1537', '4837', '3367', '7077', 'f', 'e', '1899', 'n', '2737', 'b', '8207', 'i', '9583', 'f', 'n', '3031', '6047', 'e', 'o', '3583', 'd', 'p', '3893', 'f', '7039', 'd', 'j']
A:
b, c, d, e, f, i, j, k, n, o, p, r, v, x