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:
['t', 'c', 'r', '4459', 'o', '1407', 'x', '1515', '331', 'm', '1535', 'p', 'u', 'g', '2513', 'o', '7827', '8149', 'd', 'z', 'q', '5655', 'x', '9997', '2809', 'g', 'h', '6309', 'a', 'j', '9773', '2115', 't', '9113', 'q', 'o', '427', 's', '3815', '5423', 's', 'n', 'i', 'o', '3643']

Ex Output:
a, c, d, g, h, i, j, m, n, o, p, q, r, s, t, u, x, z


Ex Input:
['2123', '6181', 'x', 'c', 'h', '8197', 'j', 'a', 's', 'v', 't', '55', '4573', '1381', '1949', 'a', '3863', 'b', 'c', 'w', '7293', '2505', 'l', 'q', '7485', '3219', '5579', '4405', 'k', '913', '4297', 'e', 'e', '6801']

Ex Output:

a, b, c, e, h, j, k, l, q, s, t, v, w, x