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]: ['3147', '9807', '5313', '6311', '737', '1555', '5803', '3437', '5665', '3973', 'o', 'f', '7871', '1721', '7833', '2933', 'b', 'b', 'n', 'm', 'k']
[A]: b, f, k, m, n, o


[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]: ['b', 'j', 'm', 'i', '961', 't', 'i', '4421', '9883', 'k', 'p', '513', 'u', 'g', 'd', '7397', '329', '8141', '5581', 's', '2963', 'd', '5307', 'y', 'm', '6905', '2363', '6875', 'c']
[A]:
b, c, d, g, i, j, k, m, p, s, t, u, y