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.

Example Input: ['u', '9249', 'u', 't', 'm', 'm', 'n', 'w', '8617', '2729', 'i', 'l', '2971', '3227', 'b', '9017', '4711', 'i', 't', 'r', 'a', 'a', '1701', '6397', '4535', '9167', '6039', '6111', '849', 'p', '8197', '2645', '5147', 'u', 'l', '7419', 'w', 'w', 'k', 'x', 'c', '3377', '4015', '1297', 'f']
Example Output: a, b, c, f, i, k, l, m, n, p, r, t, u, w, x

Example Input: ['i', '4447', 'g', 'o', 'j', 'p', 'l', 'q', 'o', '8777', 'r', 'v', '961', '6083']
Example Output: g, i, j, l, o, p, q, r, v

Example Input: ['6551', '8731', 'p', 'l', '5207', 'c', 'p', 'l', 'f', '3875', 'o', '6363', '5647', 'i', '1093', '7057', '1975', 'l', '9783', 'v', '8391', '8935', '745', 'e', '411', '2741', 'r', '411', '5653', '1133', 'a', 's', '3739', 'p', 'g']
Example Output:
a, c, e, f, g, i, l, o, p, r, s, v

