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.

['j', '425', '6223', '6631', 'y', '7649', 'r', 'a', '7933', '7947', 'l', 'l', '8755', 'g', 'b', '3351', '49', 'v', 'm', 'x', '3291', '1007', '1401', 'z', 'q', 'a']
a, b, g, j, l, m, q, r, v, x, y, z

['6737', 'g', '9985', '5257', 'k', 't', '7863', 'y', '8319', 'l', 'o', '6505', '6531', 'z', '3055', '2943', '3625', 'h', '4867']
g, h, k, l, o, t, y, z

['j', '1203', '327', 'g', 'i', 'v', '9351', 'y', 'a', 'l', 'b', '6463', '9683', '4053', '8309', 'a', 'n', '1611', '4031', 'q', 's']

a, b, g, i, j, l, n, q, s, v, y