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:
['5957', 'd', 'i', 'b', 'e', '5565', 'c', 'i', '2919']

Ex Output:
b, c, d, e, i


Ex Input:
['l', '1213', 'm', 'k', '7825', '3501', '2397', '2313', 'v', '4119', 'h', 't', '6137', 'l', '9851', 'q', '9661', 'b', 'z', '1437', '1759', 'l', '611', '5085', '4443', 'n', 'u', 'b', '2511', '6023', '7157', 'n', '9921', 'o', 'a', 'o', 'w', 't', 'o', '1607', '6751', 'n', 'b']

Ex Output:
a, b, h, k, l, m, n, o, q, t, u, v, w, z


Ex Input:
['7531', '4455', '1005', 'n', 'p', '4789', '4527', '8849', 'x', 'o', 'v', '1413', 'q', 'j', '2179', 'o', '2787', 'c', 'r', '477', 'i', 'x', '5891', '8973', 'b', '7405', '6139', '635', '6155', 'o', '1985', 's', 'l', '9107', '8863', 'd', 'j', 'd', 'h', 'a', 'q']

Ex Output:

a, b, c, d, h, i, j, l, n, o, p, q, r, s, v, x