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:
['2593', '1835', '5089', 'v', '9723', 'f', '9279', '4257', '2175', '655', 'q', 's', 'v', 'j', 'm', '4471', '6419', '1685', '2793', 'x', '509', 's', '4833', '2125', 'b', '6379', '1075']

Ex Output:
b, f, j, m, q, s, v, x


Ex Input:
['c', '4881', '6893', '3729', 'j', '2385', 'q', 'v']

Ex Output:
c, j, q, v


Ex Input:
['j', 'h', '73', '985', '2747', 'i', '2431', '4449', 'u', '5525', 'l', '1579', 'e', '7481', '1135', 'r', 'g', 'v', 'y', 't', '8469', 'r', '9927', '1325', 'l', '9529', 'g', 'j', 'p', 'e', '7199', '4407']

Ex Output:

e, g, h, i, j, l, p, r, t, u, v, y