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:
['o', '5503', '5837', '4539', '7631', 'm', '2641', 'p', '7901', '8117', 'z', '3373', '3215', 'v', 'a', '5949', 'w', '9049', 'd', 'a', 'l', 'v', 'l', 'n', 'w', 'r', 'j', '9031', '9609', '4209', 'c', '7453', '5855', '2883', '5941', 't', '4283', 'x', 'x', 'n', 'c']

Ex Output:
a, c, d, j, l, m, n, o, p, r, t, v, w, x, z


Ex Input:
['d', '4377', '9271', '8053', '9519']

Ex Output:
d


Ex Input:
['k', 'r', '4997', 'x', 'g', 't', '293', 'j', '3801', 'k', 'x', 't', 'f', '8975', '3477', '4963', '6325', 'u', 'q', 'e', '8085', '6197', 'l', 'f', '2449', '6561', '1543', '4583', 'k', 'x', '2881', 'j', '3281', '7249', '5577', '8389', 'q', 'i', 'n', 'l', '415', '5687', 'w']

Ex Output:

e, f, g, i, j, k, l, n, q, r, t, u, w, x