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.

['w', 'o', 'l', '5331', 'k', '9325', '6759', '7931', '8185', 'w', 'h', 'h', 'x', '4357', '6845', 'v', 'o', '8401', 'u', 'g', 'f', 'j', 'j', '2493', '4753', 'c', 'm', '1469', '4307', 'm', '2737', 'n', 'y']
c, f, g, h, j, k, l, m, n, o, u, v, w, x, y

['6709', 't', 'n', 'k', '991', 'a', '8899', '3563', '527', 'm', '4599', '6679', 'm', 'x', 'f', 'o', '3275', 'x', '677', 'b', '3329', '3593', '5183', '5753', 'u', '6045', '2607', 'y', '9873']
a, b, f, k, m, n, o, t, u, x, y

['8445', 'd', '4277', '9295', 'w', 'g', 'i', 'u', 'y', 'b', '7079', 's', 'a', '9611', 'g', '9519', '829', 'e', 'y', 'f', '2929', 'c', 'w', '6143', 'q', '9101', 'q', '1591', '6639', 'h', 'p', '1883', '1395', '9193', 'z', 'o', '5623']

a, b, c, d, e, f, g, h, i, o, p, q, s, u, w, y, z