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]: ['c', '9125', '6049', '5201', 'v', '9311', 'q', '3305', 'l', 'q', '3387', '3647', 'x', '471', 'a', '5631', 't', '9679', '5423', '2569', 'w', 't', '6397', 'e', 'h', 'c', 'v', 'v']
[EX A]: a, c, e, h, l, q, t, v, w, x

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

[EX Q]: ['5677', 'l', '6089', '8713', 'w', 'r', 'i', '9163', 't', '1825', '5511', '5787', 's']
[EX A]:
i, l, r, s, t, w