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: ['z', 'l', '1759', 'k', '8197', 'v', '931', '2587', '7219', '3455', 'e', '8135', 'm', 'n', 'm']

A: e, k, l, m, n, v, z
****
Q: ['b', 'a', '7411', '4471', 'z', 'l', '2051', 'q', '6749', '8647', 's', 'y', 'h', '9319', 'e', '5419', 'y', 'q']

A: a, b, e, h, l, q, s, y, z
****
Q: ['5937', 'a', '6789', 'w', 'f', 'y', '5969', 'a', 'k', 'y', '203', '1129', 'x', '1373', 'n', '7465', 'r', 'n', '8961', 'c', 'l', 'g']

A:
a, c, f, g, k, l, n, r, w, x, y
****