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:
['j', 'a', 'z', 'h', '4129', '4159', 'm', 'o', 'o', '1193', '2905', '3083', 'q', 't', 'm', 'o', '673', '7547', 'n', 'c', 'r', 't', '2897', '4959', 'z', '2377', 'y', '7977', 'u', 'b', 's', 'w', 'e', 'd', '8051']

Ex Output:
a, b, c, d, e, h, j, m, n, o, q, r, s, t, u, w, y, z


Ex Input:
['a', 'a', 'b']

Ex Output:
a, b


Ex Input:
['y', 'v', 'a', '5457', 'e', 'l', '9673', '8273', 'f', '8237', '8005', 'x', '5409', '1703', '3785', 'n', '9423', '3139', '9351', '2151', '7117', '7237', '3279', 's', '333', 'k', '1333', 'b', 's', '2531', 'g', 'x', 'c', '6541', '7259']

Ex Output:

a, b, c, e, f, g, k, l, n, s, v, x, y