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: ['4423', '8295', 'h', '4881', 'j', 'c', '1185', 'z', 'm', '2725', 'p', '9187', '6275', '1617', '2523', '9879', '4149', '2197', '3909', '5155', '691', 'r', 'e', 'u', 'l', 'd', '1581', '2763', 'c']

A: c, d, e, h, j, l, m, p, r, u, z
****
Q: ['m', '7517', '9361', '9567', '8785', 'k', '5699', '3585', 'v', '1913', '1651', 'g', 'p', '2731', 'q', 'h', '467', 'r', '1091', '9801', 'a', '6645']

A: a, g, h, k, m, p, q, r, v
****
Q: ['5399', 'r', '4393', 'o', 'x', '4635', '5393']

A:
o, r, x
****