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: ['m', '7807', 'n', 'w', '5097', '1023', '2723', 'u', '3055', '7285', 'f', 'm', 'w', '5197', '9743', '7519', '4451', 'c', 't', '1939', '5847']

A: c, f, m, n, t, u, w
****
Q: ['b', 'n', 'z', 'n', '9115', '9731', '9231', 'i', 'v', 'e', 'r', 'f', '7013', 's', 'y', 'b', '2465', '6297', 's', 'h', 'c', '7247']

A:
b, c, e, f, h, i, n, r, s, v, y, z
****