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:
['163', 'x', 'g', '5997', 'm', 'l', '7225', '7907', '375', 'y', 'a', 'j', 'c', 'j', '7755', '147', 'h', '3845', 'y', 's', 'h', 'u', '8737', '6091', 'j', 'f', 'c', '7395', '881', '1771', 'y', '3691', 'h']

Ex Output:
a, c, f, g, h, j, l, m, s, u, x, y


Ex Input:
['1707', '381', '3957', '7853', '4987']

Ex Output:
-1


Ex Input:
['v', '725', 't', 'f', 'b', 'p', '4027', 'g', '7439', 'b', '4485', '3267', '5469', 'j', 'e', '5037', 'c', 'i', '4449', '8805', 'v', 'l', 'u', 's', '9899', '3953']

Ex Output:

b, c, e, f, g, i, j, l, p, s, t, u, v