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]: ['o', '1099', 'r', '8995', 'o', '2909']
[EX A]: o, r

[EX Q]: ['9351', 'v', 'h', 'z', 'g', 'f', 't', 'q', 'g', 'o', '4073', 'n', '6149', '1735', '157', 'm']
[EX A]: f, g, h, m, n, o, q, t, v, z

[EX Q]: ['3127', '1903', '609', '1965', 'c', 'a']
[EX A]:
a, c