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: ['7073', 'd', 'e']

A: d, e
****
Q: ['f', '165', 'm', '9975', '9259', '6505', 'a', 'g', 's', '1127', 'h', 'n', 'c', '6475', 'c', '8657', 'a', '4057', 'm', 'y', 'w', 'm', '6567', '7297', '285']

A: a, c, f, g, h, m, n, s, w, y
****
Q: ['s', 'y', 'w', 'p', '2703', '9957', '2921', 'g', 'd', '7593', 'i', 'u', 'n', '8413', '2549', 'k', 's', 'q', 'h', '2247', '6099', 'z', 'g', '3333', '1851', '4055', '5069', 'u', '4261', '275', '4621', 'a']

A:
a, d, g, h, i, k, n, p, q, s, u, w, y, z
****