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:
['1985', '729', '169', '1299', 'l', 'z', '6809', '3083', 'w', 'f', '1989', 'z', '889', 'x', 'r', '1601']

Ex Output:
f, l, r, w, x, z

Ex Input:
['q', 'g', 's', 'g', 'z', '987', '777']

Ex Output:
g, q, s, z

Ex Input:
['4519', '6841', 'o', 'w', 'h', '899', '3967', 'x', 'b', '3177', '1131', '9629', 'n', '63', '3855', '1327', 'o', '9313', '5165', '3295', 'f', 'm', '147', 'e', 'g', 'q', 'z', '5659', '3749', 's']

Ex Output:
b, e, f, g, h, m, n, o, q, s, w, x, z