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]: ['8975', '7199']
[A]: -1


[Q]: ['7777', '6223', 'k', 'k', 'd', '9743', '189', '7705', 'c', '6115', '4275']
[A]: c, d, k


[Q]: ['m', '7727', '5119', '2811', 'k', 'm', 'i', 'q', 'l', '807', 'h', 'l', 'i']
[A]:
h, i, k, l, m, q