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:
['r', 'n', '7583', '8697', '7927', 'l', '5003', '1363', 'p', 'e', 'q', '6227', '6915', '8619', '9011', 'n', '3063', '3799']

Ex Output:
e, l, n, p, q, r


Ex Input:
['e', 'c', '4241', '2685', 'o', '9859', 'z', '2647', 'b', 'c', 'y', '1985', '5985', '5709', '6655', 'q', 'z', '9933', '6817', '6477', '1837', 'x', 'p', '9251', '3787', 'v', '5741', 'e', 'p', '493', '5949', '5519', 'v', 'g', '1403', 'z', 'h', 'z']

Ex Output:
b, c, e, g, h, o, p, q, v, x, y, z


Ex Input:
['n', 'e', '7513', '6425', 'f', 'o', 'h', 'q', 'u', '8605', '2279', 'k', 'y', '9461', 'p', 't', 'h', '3851', 'n', '1307', '4559', '3747', '6561', 'n', '5027', '2163', '9917', 'q', 'p', '8789', 'n', 'c']

Ex Output:

c, e, f, h, k, n, o, p, q, t, u, y