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]: ['k', 'r', 'f', '4369', 'z', 'z', 'l', '143', 'r', '707', '9167', 'g', '1749', 'i']
[EX A]: f, g, i, k, l, r, z

[EX Q]: ['j', 'f', '9567', 'f', '7383', 'k', '599', '1091', '1501', 'y', 'o', 'c']
[EX A]: c, f, j, k, o, y

[EX Q]: ['x', '5027', 'f', '51', '6655', 'b', '1741', 'f', '5675', '2613', '7503', '6879', 'u', 'u', 'b', 'j', 'u', 's', '1627', '1505', '3919', '8479', 'a', 'y', '161', '6697', '6327', '1605', '6463', '9513', 'x', 'x', 'g', '1657', '9679', 'k', '1341']
[EX A]:
a, b, f, g, j, k, s, u, x, y