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.

Input: Consider Input: ['3127', '9253', '5667', '9453']

Output: -1


Input: Consider Input: ['6655', '7445', '1795', '7495', 'h', 'z', 'u', '2199', 'r', 'p', '2245']

Output: h, p, r, u, z


Input: Consider Input: ['b', 'p', 'c', 'x', 'k', '4151', 'z', 'g', 'k', 'o', 'y', '6431', '9605', '9837', '9987', '2691', 'n', 'u']


Output: b, c, g, k, n, o, p, u, x, y, z