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: ['u', 'i', '1185', '3795', '5417', 'k', 'b', '2629', '2635', 'z']

A: b, i, k, u, z
****
Q: ['2799', '7519', '345', 'e', 'l', '9369', '4703', '4111']

A: e, l
****
Q: ['b', 'j', 'z', '9461', 'y', '3695', 'u', 'f', '3', '8641', 'z', '4277', 'i', 'x', 'u', '961', 'v', 'z']

A:
b, f, i, j, u, v, x, y, z
****