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.

Ex Input:
['m', '8127', '7519', '4543', '2809', '9855', 'n', '6241', 'w', 'w', 'q', 'w', 'p', '8599', '7819', '3817', 'm', 'q']

Ex Output:
m, n, p, q, w


Ex Input:
['8301', 'd', 'p', 'l', 'm', '9099', 'o', '8045', 'e', 's', 't', '8853', 'v', '6375', 'q', '2505', 's', '4219', '3587', 'g', '651', '7129']

Ex Output:
d, e, g, l, m, o, p, q, s, t, v


Ex Input:
['m', 'n', '4523', '6549', '2461', 'q', 'z']

Ex Output:

m, n, q, z