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.
Q: ['f', 'b', 't', 'f', '6621', '5241', '6535', '8675', 'b', 'x', '8449', '4425', 'c', '2911', '6289']
A:
b, c, f, t, x