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:
['2527', '9123', '8717']

Ex Output:
-1


Ex Input:
['z', '5601', '5675', 'w', 's', 'z', '9213', '9563', '1699', 'p', 'g', 'm', 'c', '9279', '4481', 'p', 'n', '2389', 'c', '503', '1901', '8827', '1701', '1607', '5633', 'a', 'z', 'g', '3175', 's', 'l', 'l', '6811', '1821', '693', '8277', 'q', '8623', 'o']

Ex Output:
a, c, g, l, m, n, o, p, q, s, w, z


Ex Input:
['c', '5191', 'b', '5737', 'i', '2267', '6607', 'v', '7577', 'o', 't', '5253', '907', 'v', '5991', '7505', '589']

Ex Output:

b, c, i, o, t, v