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: ['9223', 'w', '8631', '4453', '9975', 'y', '9747', 'g', '7077', '2593', '6015', 'n', '7345', 'i', '7807', '299', 'q', '3629', '2545', 'k', 'm', 'q', '5155', '5633', 'x', 'q', 'i', '27', 'f', '7919', 'p', '4835']

Answer: f, g, i, k, m, n, p, q, w, x, y


Question: ['6209', 'x', 'j', 'w', '7965', '4905', '6297', '4291', '7183', 'a', 'l', '5267', 'r', '5935', 'a', '7865', 'h', 'p', '6117', 'a', 'y', 'y', 't', 'v', '7271', 'e', 'e', 'z', 'i', 'l', '4731', '2059', 'm', '5703', 'k', 'f', '8125', 'e', '7569', 'r', '2287', '593']

Answer: a, e, f, h, i, j, k, l, m, p, r, t, v, w, x, y, z


Question: ['a', '4909', 'o', '5379', '7513', '735', '2391', '4329', 'x', 'r', '6721', '5143', 'u', 'a', 'c', '1685', 'y', '6549', 'p', '9175', 'h', '2867', 'c', 'f', 'w', '1579', 'z', '3065']

Answer:
a, c, f, h, o, p, r, u, w, x, y, z