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:
['d', 'o', '7643', '9065']

Ex Output:
d, o


Ex Input:
['o', 'h', 'z', 'n', 'e', 'y', 't', '4371', 'm', '1059', '4853', '8529', 'l']

Ex Output:
e, h, l, m, n, o, t, y, z


Ex Input:
['9917', 'c', 'h', 'k', 's', 'v', 'v', 'h', 'q', 'y', '5913', 'k', 'h', 'm']

Ex Output:

c, h, k, m, q, s, v, y