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]: ['9223', 'w', '8631', '4453', '9975', 'y', '9747', 'g', '7077', '2593', '6015', 'n', '7345', 'i', '7807', '299', 'q', '3629', '2545', 'k', 'm', 'q', '5155', '5633', 'x', 'q', 'i', '27', 'f', '7919', 'p', '4835']
[A]: f, g, i, k, m, n, p, q, w, x, y


[Q]: ['9449', 'i', '819', 'q', '4355', 'a', 'q', '4291', 'l', 'k', 'k', '5715', 'r', '3149', '9431', '7069', '2009', '3279', 'z', '3925', 'm', 'k', 'g', '2981', '6447']
[A]:
a, g, i, k, l, m, q, r, z