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:
['a', '7599', 'i', '9455', '3955', '2015', 'j', '7345', 'x', 't', 'c', '1317', '9155', '6383', '7793', 'n', '5581', 'v', '3485', 'n', 'r']

Ex Output:
a, c, i, j, n, r, t, v, x


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:
['v', 'm', 'i', 'g', '7443', '1109', '8215', '1353', '15', '7469', '5883', 'h', '5113', 'p', 'g', 'l', 'h', 'o', '237', 'c', 'c', 'j', '7713', 'y', '2037', '5183', 'g']

Ex Output:

c, g, h, i, j, l, m, o, p, v, y