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.

['t', '1905', 'p', '4431', 'y', '1107', 'e', 'x', '7413', '1189']
e, p, t, x, y