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: ['c', '7039', 'g', '1899', 'r', '507', 'c', '2587', '3865', '1729', '3927', 'r', '3535', '2791', 'm', 'l', 'r']
Example Output: c, g, l, m, r

Example Input: ['z', '3219', '6399', '2357', '7597', '357', 'k', 'k', 'u', 'd', '6115', 'w', '2921', '8809']
Example Output: d, k, u, w, z

Example Input: ['t', 'r', 'o', '2265', '135', '4885', '4623', 'l', 'z', '6355', '1567', 'n', '2617']
Example Output:
l, n, o, r, t, z