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: ['p', 'v', '1099', 'y', '1313', 's', '181', 'u', 'e', 'u', '8435', '4125', '8661', 'c', '4605', 'f', 'x']

A: c, e, f, p, s, u, v, x, y
****
Q: ['6599', 'f', 'c', '661', 'q', 'e', '1951', 'f', 'f', 'a', 'd', '9521', '853', 'n', 'w', '6451', '5549', 'k', 't', 'l', 'z', 'm', 'k', '567']

A: a, c, d, e, f, k, l, m, n, q, t, w, z
****
Q: ['w', 'z', 'g', 'v', '1021', '9347', 'g', 'n', 'e', '1429', 'q', 'c', '5227', 'h', 'j', 'm', 'j', 'd', '413', '1507', 'x', 'x', '3561', 'i', '7487', '6469', '6261', '9365', '4863', '6039', '4963', '4141', 'a', '6177', '3105', 'p', '8555', '1957', '4505', '8511', '9155', '4367', 'k']

A:
a, c, d, e, g, h, i, j, k, m, n, p, q, v, w, x, z
****