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:
['e', 'n', 'y', 'f', 'l', 'h', '455', 'y', '591', 'm', '9041', 'b', 'b', 'o', '4215', '5009', 'o', 'a', '4369', 'u', '6911', '4825', 't', 'k', '6063', '2939']

Ex Output:
a, b, e, f, h, k, l, m, n, o, t, u, y


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

Ex Output:
d, o


Ex Input:
['c', '1819', 'x', 'g', 'z', 'z', '9445', '8511', 'v', 't', '6535', '5451', 'x', '1937', '4001']

Ex Output:

c, g, t, v, x, z