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: ['u', '4731', 'l', 'p', '1997', '601', 'n', 'l', 'p', '211', '7355', '6537', 'w', 'x', '1741', '8145', '3689', 'm', 'y', '6945']

A: l, m, n, p, u, w, x, y
****
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: ['3025', 'p', 'e', '2221', 'i', 's', '4541', '8197', 'h', '5199']

A:
e, h, i, p, s
****