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.

['j', '425', '6223', '6631', 'y', '7649', 'r', 'a', '7933', '7947', 'l', 'l', '8755', 'g', 'b', '3351', '49', 'v', 'm', 'x', '3291', '1007', '1401', 'z', 'q', 'a']
a, b, g, j, l, m, q, r, v, x, y, z

['p', 'v', '1099', 'y', '1313', 's', '181', 'u', 'e', 'u', '8435', '4125', '8661', 'c', '4605', 'f', 'x']
c, e, f, p, s, u, v, x, y

['h', 'i', '6123', 'y', '8311', 'd', '8691', '1577', '8187', '2843', '6603', '9375', '2009', 'e', '2077', '7677', '3719']

d, e, h, i, y