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.

['i', '1129', 'f']
f, i

['x', '4283', 'n', 'b', 'g', 'p', '8305', '7781', '5907', 's', '1305', 'w', '8623', 'o', 'c', 'u', '1839', '2869', '7537', 'y', '2395', '5309', 'e', '4059', 'l', '6647', 'p', '9717', 'y', 'y', '3769', '2527', '2981', '5255', '4063', 'j', '4843', 'j', '9355', 'z']
b, c, e, g, j, l, n, o, p, s, u, w, x, y, z

['641', '7201', 'b', 'h', '3087', 'o', 'w', '9727', 'r', 'a', 'w', 'j', '1135', 'v', 'q', 'x', 'b', '3975', '8999', '1119', '2805', 'h', 'b', 'k', 'p', '4867', 'x', '2049', '9803', '3975', '7767', 's', '575', 'h', '7793', '8667', 'g', '7519', 'g', '4433', '2191']

a, b, g, h, j, k, o, p, q, r, s, v, w, x