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: ['o', 'c', '6469', 'x', '8815', '4441', '6193', 'u', 'm', 'a', '9879', 'p', '8335', 'c', 'z']
Example Output: a, c, m, o, p, u, x, z

Example Input: ['s', 'w', '8949', '4025']
Example Output: s, w

Example Input: ['7409', '9871', 'd', 'm', '8171', '1233', '8825', 'r', '8835', '3267', 'k', '6593', '6827', '1753', '8807', 'v', 't', '3061', '2413', '9053', '5713', 'j', 'a', '9291', 'c', '1007', '181']
Example Output:
a, c, d, j, k, m, r, t, v