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.

Q: ['w', '491', 'x', 'u', 'z', 'q', '5411', '7629', '8261', '8629', '1441', '5139', 's', 'm', '6463', 'u', 'z']

A: m, q, s, u, w, x, z
****
Q: ['477', '3931', 'g', '5967', 'm', '9845', '1607', 'a', '1749', 'k', 'j', '7945', '9125', 'v', 'n', 's', '5185', '1117', '17', 'x', '4149']

A: a, g, j, k, m, n, s, v, x
****
Q: ['6503', 'n', '4747', '6301', '2119', 'q', 'u', 'g', '1017', 'a', 'n', '3943', '9627', '2945', '8007', 'a', 'v', 'h', '9113', '5103', 'u', 'e', '79', '4665', 'r', '3803', '6249', 'c', 'o', 'w', 'n', '9751', 'k', 'i', 'a', 'o', 'u', 'k', 'l', 'k', '2585', '6445', '3599']

A:
a, c, e, g, h, i, k, l, n, o, q, r, u, v, w
****