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:
['1595', '2915', 'o', 't', 'c', 'h', '3969', '5407']

Ex Output:
c, h, o, t


Ex Input:
['n', 'h', 'h', 'e', 'p', '1265', '4853', '9433', '1227', '1619', '6381', 'o', '8285', 'k', 'u', '7471', 'm', '6887', '6579', '5813', '5563', '8535', 'n', '3743', 'h', 't', '4497', '2791', 'e', 'v', '6769', '7969', 'x', 't', 'x', 'q']

Ex Output:
e, h, k, m, n, o, p, q, t, u, v, x


Ex Input:
['6073', 'z', 'o', 'a', 'a', '6459', '1443', '4901', '7169', '7687', 'b', '5515', '7179', 'r', '9031', '8245', '8825', '6087', 'd', 'a', '6337', 'c', 'z', '7647', 'y', '4111', 'h', '7819', '5879', '4777', 'w']

Ex Output:

a, b, c, d, h, o, r, w, y, z