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: ['3223', 'h', 'w', 'f', 'y', '1667', '8843', '8759', '9203', '3305', '3549', '5507', '6251', 't', '8319', '9121', '6643', 'u', '4273', '4429', '7543', '7909', '789', '9183', '5729', 'd', '7063', 'b', '6677', 'w', 'x', 'x', 'z', '769', 'p', 'd', 'h']

Answer: b, d, f, h, p, t, u, w, x, y, z


Question: ['z', '8407', 'y', 'h', '1377', '3511', '1449', 'z', '3991', 'n', 'x', 't', 'h', '6389', '8049', '6091', '7787', 'p', 'l', '5815', 'k', 'e', 's', 'a', '9491', 'w', '1909', '4801', '4725', 'i']

Answer: a, e, h, i, k, l, n, p, s, t, w, x, y, z


Question: ['2839', '7575', 'b', '4675', 'h', '8539', 'g', 'g', '7651', 'v', '9917', 's', 'x', 'f', 'w', 'u', 'b', '9257', '8071', '1937', 'j', 'w', 'y', 'p', 'd', '307', '635', '2701', 'c', '9421', '5107', 'g', '8951', 's', 'i', 'q', '8325', 'z', '1565']

Answer:
b, c, d, f, g, h, i, j, p, q, s, u, v, w, x, y, z