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: ['9627', '9879', '5421', '4755', '1533', '6727', 't', '7641', 'd', '3929', 'h', '3989', '8441', 'k', 'p', '2653', 'm', 'b', 'i', '3431', '4907', '5687', 'g', 'h', '9185', '5051', 'k', '7135', '709']

A: b, d, g, h, i, k, m, p, t
****
Q: ['w', 'n', '729', '2491', 'n', 'x', '915', '1869', 'z', '8491', '9947', '561', '829', 'n', 't', 'i']

A: i, n, t, w, x, z
****
Q: ['9519', 'v', 'a', '7743', '8439', 'f', 'j', '6025', 'u', '4485', '9741', 'o', 'h', '8781', 'z', 'm', 'l', 'q']

A:
a, f, h, j, l, m, o, q, u, v, z
****