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: ['h', '1797', '8211', 'n', 'r', '7707', '2063', '4655', 'x', '5521', '8327', 'g', '7659', 'i', 'x', 'w', '9465', '4625', 'q', '5377', 'r', '225', 'r', 'i', 'e', '4163', 'g', 'g', '3537', 's']

Answer: e, g, h, i, n, q, r, s, w, x


Question: ['s', 'w', 'c', '4137', 't', '2437', '349', 'h', '4539', 't', 'b', 'y', 'q', 't', '9087', 'c', '9489', '6285', '6247', '8353', 'n', 't', '8661', 'p', 'z', 'p', '773', 'w', 'q', '8081', 'r', 'u', 'z', 'k', 'a', 'b', '7513', '5549', '5325', '1101', 's', '6507', '3317']

Answer: a, b, c, h, k, n, p, q, r, s, t, u, w, y, z


Question: ['3913', '5339', 'w', 'm', 'z', '5933', 'r', 'c', '6581', 'r', 'v', '3569', '6271', '8743', '8201', '4965', '8805', '6887', 'c', '9657', 'd', 'e', '9119', 'w', 'v', '6537', 'v', 'w', '999', '4205', '9643', '7331', 'n', '8945', 'h', '9617', '7637', 'f', '4281', '1237', '9143', 'k', 'j']

Answer:
c, d, e, f, h, j, k, m, n, r, v, w, z