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.

['5957', 'd', 'i', 'b', 'e', '5565', 'c', 'i', '2919']
b, c, d, e, i

['2313', '2073', 'd', 'e', 'o', '793', '4999', 'f', 'c', '4473', '4519', 'u', 'n', 'k', '69', '475', 'a', 'j', 'q', 'x', '5869', '9523', 'z', 'v', '9265', '5989', 'p', 'm', 'g', 'y', 'b']
a, b, c, d, e, f, g, j, k, m, n, o, p, q, u, v, x, y, z

['659', 'g', '893', '7657', 'w', '3627', 'y', 'm', '9463', 'j', 's', '4561', '5441', '157', 'w', 'o', '9037', '9015', '6641', '8625', 'o', 'w', 'm', '6319', '7867', 'a', '1683', '1795', 'a', '1201']

a, g, j, m, o, s, w, y