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.

Input: Consider Input: ['7367', '9757', '9431', 'h', 'a', 'k', '5833', '6237', 'g', '3585', '8665', 'g', '7517', '1561', 'p', 'p', '1307', '3325', 'q']

Output: a, g, h, k, p, q


Input: Consider Input: ['4925', '9943', '7935', '4387', '2449', '5797', 'i', '1517', 'w', 'e', '9525', 'y', 't', 'e', '2793', 'v', '9897', '8709', '7247', 'o', 'f', '5549', 'q']

Output: e, f, i, o, q, t, v, w, y


Input: Consider Input: ['b', 't', '9823', 'p', '7559', 'p', 'd', 'k', 'k', 'g', 'o', '8505', 'p', 'i', '5929', '2993', 'i', 'w', 'd', '4245', 'e']


Output: b, d, e, g, i, k, o, p, t, w