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:
['c', 'e', '6509', '1295', 'u', '5445', '1731', '3049']

Ex Output:
c, e, u


Ex Input:
['7187', '7081', 'j', 'i', '3725', '6333', 'h', 'f', '6639', 'r', 'n', '3559', '2785']

Ex Output:
f, h, i, j, n, r


Ex Input:
['6655', '7445', '1795', '7495', 'h', 'z', 'u', '2199', 'r', 'p', '2245']

Ex Output:

h, p, r, u, z