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: ['e', '1251', 'y', '6689', '6389', 'h', 't', '503', '5093', 'e', '923', '7051', 'm', 'u', '4501', '3289', '6887', '8341', 'o', '3671', 'n', 'w', '7749', 's', 'j', 'o', '8429', 'q', 'v', 'p', 'd', 'g', 'i', 'f']

Output: d, e, f, g, h, i, j, m, n, o, p, q, s, t, u, v, w, y


Input: Consider Input: ['8821', '9833', 'l']

Output: l


Input: Consider Input: ['1807', '7775', '5731', 's', 'e', '3453', '5961', '9187', 'y', 'm', '7729', '9535', '8433', '4359', '3083', 'p']


Output: e, m, p, s, y