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: ['8315', 'b', '4333', 'f', '6507', '6211', '3475', 'c', 'e', '8039', '661']

A: b, c, e, f
****
Q: ['7411', '9671', '6773', '8409', '6589', '9017', '3175', '7691', 'u', '8065', '2275', '1951', '7519', '2635', '7767', '1933', '6869', '2929', 'n', 'a', '9523', '517', '7221', 'n', 's', '7561', 'c', 't', 'z']

A:
a, c, n, s, t, u, z
****