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: ['2247', 'w', 'h', '4675', '6153', 'f', '6029', 'o', 'd', 'j', 'z', 'y', 'i', '6899', '3917', 'u', '6447', '6405', 'a', '1705', '8585', 'v', 'f', 'r']

A: a, d, f, h, i, j, o, r, u, v, w, y, z
****
Q: ['2819', 'k', 'u', 'a', '4575', 'a', 't', 'a', 'f', '1507', '415', 'w', 'o', 'o']

A: a, f, k, o, t, u, w
****
Q: ['u', 'o', 'k', 'h', '2291', 'v', '949', '5361', 'm', 'f', 'o', '9183', '3863', 'c', 'z', 'q', '4851', '4211', 'g', 'n']

A:
c, f, g, h, k, m, n, o, q, u, v, z
****