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: ['v', '3765', '4065', 'a', '4201', 'f', 'x', '9275', 'q', '9303']

A: a, f, q, v, x
****
Q: ['1749', 'i', 'w', 'j', '3171', '1999', '1037', '4937', '7013', '3593', '287', 'o', 'i', 'j']

A: i, j, o, w
****
Q: ['m', 'f', '9695', '329', '7913', 'i', '3601', '4805', 'o', '3991', '4607', '6541', 'z', '5801']

A:
f, i, m, o, z
****