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:
['9271', '6393', '6005', 'x', '2301', '3999', 'p', 'z', 'j', '1033', '7555', 'r', 'r', 'y', '8917', '5939', '4031', 'e', '8095', 'g', '6095', 'a', '4133', '6471', '2129', '8021', '1093', 't', '8805', '545', 'k', '3249', 'l', '1561', '9909', 's', '1963', 'o']

Ex Output:
a, e, g, j, k, l, o, p, r, s, t, x, y, z


Ex Input:
['w', '1367', '5389', '9515']

Ex Output:
w


Ex Input:
['c', '7359', 'm', 's', 'o', 'r', '453', 'g', 'c', 'o']

Ex Output:

c, g, m, o, r, s