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:
['u', 'k', 'd', '4393', 'u', 'h', 'q', '833', 'k', 'l', '5749', 'r', '7123', '1003', 'z', '531', 'o', 'u', '6601', '6975', '4905', 'n', 'e']

Ex Output:
d, e, h, k, l, n, o, q, r, u, z


Ex Input:
['1801', 'q', '5101', '8863', '2309', 'p', '8789', '9529', '6135', '5523', 'f', '8889', '7639', 'k', '263', '5751', '5529', 'g', '1451', '4143', 'e', '6987']

Ex Output:
e, f, g, k, p, q


Ex Input:
['6839', '4691', 't', 'w', '6859', 'b', '1627', 'l', 'r', 's', '893', 'g', '4109', 'w', '6085', 'd', '7393', '2923', '581', '8945', '3117', 'i', '1969', 't', 'f']

Ex Output:

b, d, f, g, i, l, r, s, t, w