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.
--------
Question: ['9351', 'v', 'h', 'z', 'g', 'f', 't', 'q', 'g', 'o', '4073', 'n', '6149', '1735', '157', 'm']

Answer: f, g, h, m, n, o, q, t, v, z


Question: ['5345', 'f', '6605', 's', 'q', 'w', 'p', 'o', 's', 'u', 'i', '7339', '8379', 'h', '9547', 'b']

Answer: b, f, h, i, o, p, q, s, u, w


Question: ['8043', 'n', 'l', '1733', '8539', '6001', 'g', '3055', '1703', '9121', 'g', '4055', '9279', 'i', '4269', 'g', '71', 'i', '7595', '3671', 'm', '8841', '891', 'y', 'z', '8507', '7193', 'o', 'k', '511', 'l', '2049', 'i', '9201', 'q', '8937', 'x']

Answer:
g, i, k, l, m, n, o, q, x, y, z