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.

[EX Q]: ['x', 'b', '1467', 'y', '2101', 'y', 'm', '2745', 'z', '429', '7523', 'e', 'f']
[EX A]: b, e, f, m, x, y, z

[EX Q]: ['231', 'r', '5673', 'j', '589', 'z', '4659', 'a', '3763']
[EX A]: a, j, r, z

[EX Q]: ['3001', 'x', 'j', '2971', '1107']
[EX A]:
j, x