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:
['5737', 'b', 'e', 't', '7419', 'n', 'y', '5225', '6485', 'b', '1343']

Ex Output:
b, e, n, t, y


Ex Input:
['p', 'g', 'q', 'e', '8045', '9999', '9555', '7995', '7195', 'z', 't', '5223', '3699', 'i', '4797', '3817', 'x', 'y', 'w', 'o', '8915', '7803', 'n', '1117', 'c', '9647', 'p', 'e', '9669', '4845', '9255', '4545', '3693', '6871', 'w', '4327', '3285', 'k', 'f', 'x', 'i', 'b', '5967', '6601']

Ex Output:
b, c, e, f, g, i, k, n, o, p, q, t, w, x, y, z


Ex Input:
['9301', 'b', '6853', 't', '431', '9537', 'v', 'l', 'z', '3059', 'z', 'w', 'm', 'v', 'v', '5547', 'z', 'k', '7537', 'v', '1033', 's']

Ex Output:

b, k, l, m, s, t, v, w, z