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: ['f', 'p', 'n', '839', '9229', 'r', '7661', 'c', '4383', 'u', 'k', '5321', '3181', '1785', 'w', 'k', '8721', '7855', '4093', '6495', 'q', '2467', 'g']

A: c, f, g, k, n, p, q, r, u, w
****
Q: ['o', '1099', 'r', '8995', 'o', '2909']

A: o, r
****
Q: ['j', '9385', 'x', '99', '4305', '8223', '3603', 'k', '3603', '3937', '2309', '713', 'l', 'j', 'e', 'i', '4279', '1727', '7665', 'z', 'f']

A:
e, f, i, j, k, l, x, z
****