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: ['o', 'm', '8015', '787', '4787', '1727', 'f', 'e', 'c']

A: c, e, f, m, o
****
Q: ['2505', '4199', 'e', '5433', '8795', 'q', 'i', '9357', 'o', '257', '8235', 'b', '1339', 'w', '1463', 'm', '277', '3211', '3863', 'r', 'm', 'i', '5793', '7451', '4787', '4739', 'k', 't', 'o', '7453', '9385', 'v', 'l', 'y', 'f', 'r', 'p', 'w']

A: b, e, f, i, k, l, m, o, p, q, r, t, v, w, y
****
Q: ['b', '3429', '5523', 'o', 'w', '1929', 'k', '2841', 'l', 'd', 'z', '3009', 'i', 'u', '8837', 'b', 'l', '7019', '487', 'p', '8223', 'w', '871', 'n', '2349']

A:
b, d, i, k, l, n, o, p, u, w, z
****