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:
['o', 'm', '8015', '787', '4787', '1727', 'f', 'e', 'c']

Ex Output:
c, e, f, m, o


Ex Input:
['l', 'o', 's', '7411', '7847', '2557', '1977', '2863', '2325', '4177', '4183', '4241', '1005', '1137', '1371', 'v', 'p', 'a', '2453', 'l', '6315', 'l', '6463', 'n', '7645', '9669', '5411', '1631', '5995', 'z', '227']

Ex Output:
a, l, n, o, p, s, v, z


Ex Input:
['9035', '765', '9359', 'p', '6643', 'd', 'v']

Ex Output:

d, p, v