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: ['3797', '6117', 'x']
Example Output: x

Example Input: ['2381', 'y', '6631', '5839', 'r', 'm', 'z', 'b', '4663', '595', '7771', '5305', '5087', '3317', '3125', '9551', '4343', '5121', 'm', 'i', '131', '8401', '5379', '1775', 'u', '1125', '9793', '4123', 'h', '1613']
Example Output: b, h, i, m, r, u, y, z

Example Input: ['g', 'i', 'u', 'd', '6559', 'n', '7421', '4363', '8711', '903', 'a', 'j', 'a', '303', '8609', '1847', 'l', 'x', 'x', 'r', 'i', 'i', '929', 's', 'n', 'r', '3265', '941', '1013', '719', 'a', 'a', 'l', 'j']
Example Output:
a, d, g, i, j, l, n, r, s, u, x