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.

['8315', 'b', '4333', 'f', '6507', '6211', '3475', 'c', 'e', '8039', '661']
b, c, e, f

['e', 'k', '7569', '6387', '4593', '2445', '345', '2905', 'h', '3119', '7001', 'x', 'a', '2943', '3635', 'l', 'q', 'z', 'g', '2657', '7849', 'i', '9413', 'm', 'e', '2951', 'd', '2963', 'b', 'u', 't', 'i', '1141', 'c', 'm', '8607', 's']
a, b, c, d, e, g, h, i, k, l, m, q, s, t, u, x, z

['5575', '2137', '8359', 't', '5705', 'e', '5671', '4839', 'q', 'j', 'e', 'z', 't', '5081', 'c', '7577', 'u']

c, e, j, q, t, u, z