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:
['z', '8763', '6399', '45', '6731', 'v', '441', '4763', 'u', '8741', 'r', '9143', 'd', 'p', '2241', 'y', '6523', 'y', 'w', '6771', 't', 'r', '9239', '295', 'z', '461', 'b', '9217', '2597', '1249', 'r', 'i']

Ex Output:
b, d, i, p, r, t, u, v, w, y, z


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

Ex Output:
w


Ex Input:
['5641', 't', '6303', 'y', '957', '4137', '4331', 'u', 'j', '7487', 'j', '8221', '437', '9603', '1921', 'g', '9079', '8171', '2525', '7465', '1753', '8635', '7657', '9381', '4999', 'u']

Ex Output:

g, j, t, u, y