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:
['2459', '3709', 'f', '8673', '9313', 'm', 'd', 'g', 'c', 'g', 'u', 'f', 'p', 'i', '8771', '3613', '9669', '6221', '1211', '8331', '2295', 'b', 'f', 'm', '1377', '9831', '1751', 'k', '4831', 'm', '2747', '3435', '4543', 'c', '1729', 'e', '7093', '397', 'm', '383', '2019']

Ex Output:
b, c, d, e, f, g, i, k, m, p, u


Ex Input:
['m', '5005', 'y', 'h', 'w', '3609', 'p', '2539', '3307', 'p']

Ex Output:
h, m, p, w, y


Ex Input:
['8855', '903', '2453', 'k', 'n', 'o', '5655', '2907', '9825', '6841', '6527', '1465', '7533', 'y', 'n', '1601', 'k', 'o', 'g', '9385', 'n', '4939', '8937', 'w', '1359', '2963', '6103', '9939', 'g', 'l']

Ex Output:

g, k, l, n, o, w, y