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: ['3797', '6117', 'x']

A: x
****
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']

A: a, c, e, h, l, q, t, v, w, x
****
Q: ['c', 'f', '5781', 'z', 'z', 'a', 'h', '9839', '327', 'a', '3407', '2893', '4205', '4521', '7119', '4351', 'q', '2173', 'g', 'y', 'l']

A:
a, c, f, g, h, l, q, y, z
****