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.
--------
Question: ['w', '1349', '3393', '7507', '2469', '8531', 'w', '6845', 'k', 'q', '2401', 'f', 'g', 'l', 'n', 'n', 'e', 'q', 'y', 'v', '3077', '4167', 'b', '5517', 'b']

Answer: b, e, f, g, k, l, n, q, v, w, y


Question: ['j', '1733', 'p', '6741', '7933', '8943', '733', 'x', '1107', 'z', '1719', '7653', 'y', 'z', '6563', 'p', '4615', 'j', '4489', 'h', 'w', 'y', 'p', 'c', '7949', 'k', 'm', 'r', '9427', '7243', '9777', 'j', '323', '4095', 't']

Answer: c, h, j, k, m, p, r, t, w, x, y, z


Question: ['l', 'w', 't', '4513', 'o', '2773', '4395', '7201', 'x', '1383', '8223', 'l', '545', '311', '5471', '2795', '6145', 'i', '1679', '2957', '6725', 'f', 'k', 'g', 'f', '4667', '4525', 't', '2657', 'w', 'n', '2977', 'q', '4623', '8043', 'f', '4243', '5659', '719', '5357', '3441']

Answer:
f, g, i, k, l, n, o, q, t, w, x