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:
['5159', '6407', '4021', '6655', 'c', 'k', 'w', '7191', 'l', '4321', '1609', 'm', '1991', '9261', '511', 'p', '7495', 'b', 'e', '4647', '2711', 'd', 'y', '3835', '5037', '3613', '2695', '3367', 'm', 'j', 'y', '9561', '4889', 'a', 'z', '2253', 'p', 't', 's', '8371', '2859', 's']

Ex Output:
a, b, c, d, e, j, k, l, m, p, s, t, w, y, z


Ex Input:
['8315', 'b', '4333', 'f', '6507', '6211', '3475', 'c', 'e', '8039', '661']

Ex Output:
b, c, e, f


Ex Input:
['3751', '9635', 'h', '7953', 'n', '2795', 'i', '77', '5539', 'r', 'v', '4087', 'd', 'i', 's', '2125', 'i']

Ex Output:

d, h, i, n, r, s, v


