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.

['6603', 's', '4285', 'b', 'q', '4737', 'a', '2393', '5609', '6497', 'o', 's', '2283', 'k', '8537', 'p', '9755', '9023', '1157', '3451', 'u', 'v', 'e', 'f', '6245']
a, b, e, f, k, o, p, q, s, u, v