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:
['j', 'y', '9907', 'a', '5715', 'l', '9817', '1949', '2697', '2255', '9571', '8957', '9329', '6055', 'z', 'q', '1185', '4593']

Ex Output:
a, j, l, q, y, z


Ex Input:
['n', 'h', 'j', '5945', '8511', 'y', '7739', '4717', '2483', 'p', '9545', '7647', '9863', '5591', '5393', 'i', '9225', '589', '1497', 'j', 'm', '2397', 'a', 'd']

Ex Output:
a, d, h, i, j, m, n, p, y


Ex Input:
['d', '4711', '5025', 'y', 'f', 'z', '2047', 't', 'b', 'u', 'u', '3297', 'h', 'h', 'f', '1299', 'd', 'q', '8267']

Ex Output:

b, d, f, h, q, t, u, y, z