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

[EX Q]: ['e', 'z', '5199', 'x']
[EX A]: e, x, z

[EX Q]: ['2041', '7759', 'r', 't', 'z', '7391', 'p', 'o', 'k']
[EX A]:
k, o, p, r, t, z