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


[Q]: ['5161', 'v', 'y', '6005', 'y', 'l', '5451', 'z', 'j', 'd', '4597', '9319', '1241', 'g', 'f', 'b', 'g', '683', '763', 'm']
[A]: b, d, f, g, j, l, m, v, y, z


[Q]: ['5863', '5805', '9819', '6915', '33', 'k', '3431', 'c', 'c', '7143', '2649', '7045', 'h', 'g', 'f', '6489', '577', 'y', 'r', '6779', '373', 'i', '6979', 'r', '4657', '1085', 'v', '7943', 'o', 'n', 'j', 'h', 'm', '3889', 'x', 'j', 'k', 'a', '2625', 'p', 'x', '8149', '2611']
[A]:
a, c, f, g, h, i, j, k, m, n, o, p, r, v, x, y