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: ['y', 'b', 'r', 'f', '3745', 'n', '2921', '8133', 'r']

A: b, f, n, r, y
****
Q: ['395', '8309', 'v', 'r', 'x', 'j', 'l', 'b', 'c', 'c', '3123', 't', 'a']

A: a, b, c, j, l, r, t, v, x
****
Q: ['4923', 'q', '9791', 'l', 'o', '1691', 'v', '2717', '6295', '5761', '7731', '1827', '31', '6853', 'k', '9419', '349', 's', 'f', '5895', '6211', '5611', '2919', 'a', 'e', 'k', 'y', '6213', '2047', '5679', 'f', '6459', '1481', 'a', 'y', '6065']

A:
a, e, f, k, l, o, q, s, v, y
****