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.

[Q]: ['i', '9215', 'n', 'p', '4815', '8757', 'm', '1755', 'c', 'z']
[A]: c, i, m, n, p, z


[Q]: ['1345', 'y', '7221', 'h', 'r', '3255', 'k', 'r', 'j', '8639', '467', 'f', 'k', 'n', 'k', 'j', 'l', 'w', '143', 'w', 'q', '5657', '589']
[A]: f, h, j, k, l, n, q, r, w, y


[Q]: ['2395', '5129', 'c', 'x', '2761', 'k', 't', 's', 'v', '1075', '3673', 'x', 'l', 'a', 'e', '9373', '5173']
[A]:
a, c, e, k, l, s, t, v, x