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]: ['s', 'c', 'e', '2457', '9413', 'r', '9949', 's', 'z', 'e', 'a', 'o', '7207']
[EX A]: a, c, e, o, r, s, z

[EX Q]: ['2165', 'f', '5081', 's']
[EX A]: f, s

[EX Q]: ['691', 'h', '9125', '7121', 'z', 'j', '4063', 'v', 'y', '3497', 'a', '2163', 'r', '591', '5207', 'h', 't', 'k', '7247', 'l', 'e', 'k', '4407', '2813', '8415', 'x', '6913', '9961', 'k', 'u', '7869', 'u', '23', 'n', '197', 'r', 'e', '8839']
[EX A]:
a, e, h, j, k, l, n, r, t, u, v, x, y, z