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:
['3117', 'i', 'd', '7537', 'i', 'q', '4649', '7263', '3655', 'd', 'x', '8569', 'g', '2389', '3933', '7099', '563', '3055', '9941', 'm', 'c', '3529', '3577', 'x', 's', 's', '6153', '1731', '9679', 'f', '8839', '5183', '5', '6433']

Ex Output:
c, d, f, g, i, m, q, s, x


Ex Input:
['4269', '1847', '2025', '601', 'g', 'n', 'h', '3499', '4977', '3579', '9355', '3489', 'm', 'm', '4401', '4605', 'l', '3977', 'h', 'd', 't', '5135', '7787', 'k', 'q', '7699', '5325', '6269', '1865', 'h', '8915', '5677', 'g', '603', '1435']

Ex Output:
d, g, h, k, l, m, n, q, t


Ex Input:
['6491', '9847', '2161', '5725', 'g', 't', '8017', 'f', '587', '145', '8061', '7455', 'z', '5013', 'h', '2851', '6513', '827', '4121', 'y', 'n', '1533', '3593', 'j', '8293', 'y', '4381', '6943', '867']

Ex Output:

f, g, h, j, n, t, y, z