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:
['a', 'w', 'm', 'g', 'c', '5475', '7391', 't', '1049', 'p', 'd', '1397', 'k', 'x', 'j', '2525', 'f', '741']

Ex Output:
a, c, d, f, g, j, k, m, p, t, w, x


Ex Input:
['i', 's', 'f', 'i', '2293', '245', '4983', 'h', 'h', '6203', '8703', '1613', 'h', 'o', '3635', '8069', '2829', '1939', 'u', 'm', '5305', 'n', 'k', '9367', 'u']

Ex Output:
f, h, i, k, m, n, o, s, u


Ex Input:
['f', 'k', '5269', 'm', 'p', 'c', '2481', 'b', 'j', '3905', 'b', '9945', 'n', '2549', '3791', '9785', 'u', 'l', 'l', 'n', 'p', 'c']

Ex Output:

b, c, f, j, k, l, m, n, p, u