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: ['w', '743', '5757', '8731', 'k', 'p', '317', 'n', 'x', '5649', 'l', 'm', 'c', '2499', 'l']

A: c, k, l, m, n, p, w, x
****
Q: ['7653', 'n', '697', '4565', 't', '7275', '2429', '1365', '7059', 'o', '8053', 'j', '2837', '957', '851', 'z', 'd', 'd', 'y', 'c', '7467', 'o', 'i', '9519', 'q', 'g', '7911', 't', 'g', '3439', '5821', '8433', 'k', 'z', 's', 'g', '685', 'i', 't', 'r', '6881']

A: c, d, g, i, j, k, n, o, q, r, s, t, y, z
****
Q: ['n', 'p', '3303', 'n', 'l', 'k', 'x', '5477', 'u', '3293', 'f', 'b', '9349', '5347', '397', '9131', 'w', 'a', 'e', 'e', '7125']

A:
a, b, e, f, k, l, n, p, u, w, x
****