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.

['f', '6817', 'f', 'd', '3835', '3051', 'u', 'l', '7679', 'b', '3931', '1441', 'q', '8675', 's', '5487', 'y', '2279', 'x', 'y', '9513', '2875', '1771', '879', '2927', '3469', 'v', 't', 'k', '9991', '2565', '7345', '973', 'w', 'i', '6105']
b, d, f, i, k, l, q, s, t, u, v, w, x, y

['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']
f, g, i, k, m, n, p, q, w, x, y

['d', 'v', '7355', '5837', 'v', '7541', 'x', 's', 'n', '6319', 'w', 'y', '5567', '5155', 'd', 'j', '3931', '8809', 'k', 'e', 'p', 'i', 'f', 'j', '3941', '4553', 'i', 'j', '8431', '4619', 'y', 'm', 'k', '7141', 'f', 'c', '1939', '6021', 'v', 'o', 'f', 'd', '3173', '2229']

c, d, e, f, i, j, k, m, n, o, p, s, v, w, x, y