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', '4169', 'k', '7349', 'w', 't', '8271', '8781', '3725', '2865', '6053', 'j', 'z', '4211', '8231', '213', '6389', 'f', 'h', 'g', '9269', '4617', '4137', 'i', 'y', 'i', 'n', '4597', 'p', 'z', '3195', '3231', 'c', '1901', '1231', 'p', '4509', '2557', '3715']

Ex Output:
c, f, g, h, i, j, k, n, o, p, t, w, y, z


Ex Input:
['7997', 'm']

Ex Output:
m


Ex Input:
['w', '9995', '6849', '2643', '6477', '8317', 'a', '2321', 'y', '5653', '1491', '3517', '1659', '7509', '6831', 'r', '9127', 'w', 'n']

Ex Output:

a, n, r, w, y