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', '6537', '4063', '6413', 'k', 'd', '2479', 'p', '2251', 'q', '7079', 'r', 'd', 'p', '3347', '1391', '9847', '4487', 'u', '6951', '5285', '5837', '6747', 'r', 's', 'c', 'x', 'b', 'q', 'y', 'd', '331', '679', 'v', '1919', 'f', 'p', '1267', '3151']

Ex Output:
b, c, d, f, k, m, p, q, r, s, u, v, x, y


Ex Input:
['5011', 'l', '925', 'e', 'b', '3077', 'm', '4541', '781']

Ex Output:
b, e, l, m


Ex Input:
['6733', '4223', '9443', '1365', 'y', '7733', 'g', '3053', 'j', 'v', 'v', '5823']

Ex Output:

g, j, v, y