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: ['9351', 'v', 'h', 'z', 'g', 'f', 't', 'q', 'g', 'o', '4073', 'n', '6149', '1735', '157', 'm']

A: f, g, h, m, n, o, q, t, v, z
****
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: ['6117', '7153', '5939', 'o', '9005', 'i', 'a', 'k', 'j', '4601', 'c', 'j', '5535', 'p', '4033', 'q', '3397']

A:
a, c, i, j, k, o, p, q
****