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.

['g', 'x', 'l', 'e', 'd', '1345', '1763', 'm', 'c', '2057', 's', 'a', '4127', 'y', 'h', '8581', 'o', '9203', '4761', 'd', 'u', 'n']
a, c, d, e, g, h, l, m, n, o, s, u, x, y

['9555', '5983', '1853', 'c', 'z', 't', 'p', '9041', 'd', '5919', '1621', '345', 's', '2647', '4261', '8611', 'w', 'x', 'p', '9103', '2599', '5101', '9261', 'k', '7437']
c, d, k, p, s, t, w, x, z

['9715', 'o', 'j', '5647', 't', 'p', '7219', '6667', 'u', '3583', 'q', '4935', '4519', 'a', 'w', 'g', '4951', 'n', 'g', 'p', '4781']

a, g, j, n, o, p, q, t, u, w