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: ['7997', 'm']

Output: m


Input: Consider Input: ['2077', 'e', 'w', '1227', 'y', '2931', 'l', '4461', '8789', 't']


Output: e, l, t, w, y