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.

Q: ['5553', 'f', '3881', '8867', 's', 'd', 'a', '375', '7889', '3949', '2905', 'w', 'q', 'q', 'd', '4203', 'i', '2601', 'y', 'p', 'k']

A: a, d, f, i, k, p, q, s, w, y
****
Q: ['q', '8149', '4087', '5183', 't', 'j', 'e', 'g', 'r', '2125', 'y', 'l', 'g', '3673', 's', 'r', 'e', 'v', '4259', 'v', '3477', '9353', '3639', 'v', 'n', 'e', 'z', '5071', 'x', '6287', 'e', 'e']

A: e, g, j, l, n, q, r, s, t, v, x, y, z
****
Q: ['1031', 'w', 'c', '1831', 'r', '9735', '4861', '5557', '6825', '9989', '9783', '793', 'v', '3971', '6841', '5863', '8937', 'y', 'g', '2849', '9007', '5285', '4349', '7833', '3805', '5285', '7611', '4243', '8389', '7157', 'l', '7991']

A:
c, g, l, r, v, w, y
****