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:
['2381', 'y', '6631', '5839', 'r', 'm', 'z', 'b', '4663', '595', '7771', '5305', '5087', '3317', '3125', '9551', '4343', '5121', 'm', 'i', '131', '8401', '5379', '1775', 'u', '1125', '9793', '4123', 'h', '1613']

Ex Output:
b, h, i, m, r, u, y, z


Ex Input:
['333', 'b', '261', 'k', 'p', '7861']

Ex Output:
b, k, p


Ex Input:
['7717', '6095', '6191', '9777', 'o', 'x', 'x', '5473', 'd']

Ex Output:

d, o, x