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: ['5499', 'v', '6507', 'w', 'c', '8431', '8861', '5391', '4765', '4295', '1865', '485', '7255', '1205', 'p', 'w', 'q', '6833', '959', 'a', 'i', '2599', '7779', 'h', '9651', 'g', 'r', 'e', 'u', '4511', '1587', '5601', '8287', '5685', 'u', 'g', '2853', 'p', 'k']

Answer: a, c, e, g, h, i, k, p, q, r, u, v, w


Question: ['d', 'a', '6931', 'c', 'u', 'z', '9713', 'v', 'm', 'e', 'k', 'o', '9705', 'a', '5373', 'c', '2983', '8097', 'h', '3039', 'g', 'f', 'n', 'v', '853', '8227', '7573', 'j', 'h', 'k', 'o', 'k', '8897', 'd', 'g', 'd', 'd', '4039']

Answer: a, c, d, e, f, g, h, j, k, m, n, o, u, v, z


Question: ['2653', '215', '5347', '8755', '3061', '9431', '7141', 'c', '2757', '9499', 'b', 'y', 'x', 'f', '5881', '1295', 'c', '423', 'v', 'e', 'a', 'r', 'm', '5081', 'j', 'q', 'z', '363', 'f', 't', 'r', 'd', '5733', '8015', '1073', '5147', '3219']

Answer:
a, b, c, d, e, f, j, m, q, r, t, v, x, y, z