Detailed Instructions: 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.
Problem:['6945', 'j', '2211', 'x', 'a', 'n', '4953', '7969', '2583', 'g', '9529', 'j', '8151', '9455', '6135', '2239', 'm', '5725', 't', '553', 'g', '4055', 'r', 'k', '6737', '7721', '257']
Solution:
a, g, j, k, m, n, r, t, x