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: ['7155', 'y', '145', '7147', 'u', '8453', 'd', '3693', '6471', '5289', 'n', 'p', '8289', '2929', '199', 'e', '8377', '8937', '5315', 't', 'l', '7715', 'c', 'y', 'f', '9999', 'p', '3655', '5489', 'q', '2321', '9881', '2265', 'n', 'v', '455']

A: c, d, e, f, l, n, p, q, t, u, v, y
****
Q: ['a', 'a', 'b']

A: a, b
****
Q: ['q', '8929', 'z', '531', 'z', 'v', 'o', '6995', 'a', 'x', 't', '4149', 'k', 'o', '8653', 'q', '3897', 'y', '6407', 'y', '2561', 't', '9501', 'u', 'w', '4225', 'o', '1541', '3215', 'd', 'u', 'p', 'w', '6045', 'v', 'o', '1279', '4309', '6785', '3831', '6027', '8615']

A:
a, d, k, o, p, q, t, u, v, w, x, y, z
****