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]: ['r', '9489', 'e', 'n', '6323', 'd', '3163', '265', '8587', '7891']
[EX A]: d, e, n, r

[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]: ['5291', 'l', '9991', '9725', '1381', 'b', '4909', 'j', '533', '9961', '9651', 'p', '5869', 'm', 'e', 'c', 'f', 'h', '3619', '5013', 'c', 'x', '4597', '4623', 'i']
[EX A]:
b, c, e, f, h, i, j, l, m, p, x