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: ['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: ['653', '1969', '6235', '6283', 'd', 'e', '465', 'e']

Answer: d, e


Question: ['3577', 'u', 'l', '9633', '6569', '5495', 'd', '2461', 'u', '2561', '7415', '697', 'c', 'h', 'n', 'o', '3161', 'i', 'y', '3093', 'n', '6629', 'z', '4201', 'v', '9847', 'v', '7359', '1443', '3661', '1207', 'n', '9859', '2201', 'd', '4059', '6163']

Answer:
c, d, h, i, l, n, o, u, v, y, z