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.

Ex Input:
['p', '9641', '8515', '1207', 'd', 'j', '6617', '5529', 'g', 'a', 'o', 'f', 'y', '4993', '4643', '6087', 'n', '3177', 'y', '9471', '1229', '8211', '7079']

Ex Output:
a, d, f, g, j, n, o, p, y


Ex Input:
['1649', 'l', 'i', '5901', 'o', 'g', '1197', 'a', '9327', '9835', '1095', 'k', '4489', '9149', 'o', '3095', 'z', 'u', 'y', '561', '7419', 't', 'j', '8763', 'v', '339', 'y', 'w', 'v', 'v', '1867', 'd', 'r', 'w', 'h', 'j', '1531', '3841']

Ex Output:
a, d, g, h, i, j, k, l, o, r, t, u, v, w, y, z


Ex Input:
['3743', 'l', '6819', 'o', '1445', '4457', '5283', '8207', 'k', '6123', 'y', '8917', 'n', '3495', '4355', 'i', '4797', 'f', '1047', '367', 'q', 'p', 'j', '6837', 'o', '1151', 'j', '3049', 'z']

Ex Output:

f, i, j, k, l, n, o, p, q, y, z