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: ['1449', 'a', '6261', '303', '4651', 'n', 'u', '1595']

A: a, n, u
****
Q: ['e', '2239', 'l', '8309', 'i', '2613', 'i', '611', '6481', 'j', 'v', '1867', '415', '269', '8053', '3369', 'q', 't', '2303', '7729', '1059', '6135', '3299', 'd', '6855', '207', '6227', '7859']

A: d, e, i, j, l, q, t, v
****
Q: ['i', 'h', 'b', 'o', 'e', '8563', '9391', 'j', 'x', 'k', '853', 'n', '7183', 'k', '8569', 'y', '6157', '5415', '5593', '3549', '5343', 'i', 'i', '1717', 'r', '8051', 'x', '9117', '2003', '2847', '4529', 'n', '9629', 's', 'k']

A:
b, e, h, i, j, k, n, o, r, s, x, y
****