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: ['8129', 'a', '4245', 'y', 'm', 'a']
Example solution: a, m, y
Example explanation: Here, the unique alphabets in the list are 'a', 'y', and 'm', hence their sorted order is 'a, m, y'.

Problem: ['9927', '2061', 'a', '175', '2561', '9093', 'f', '8675', 'x', '6979', 'g', '287', '9053', 'v', '4981', '7849', '7373', 'j', 'k', '5713', '8413', 'm', '7445', 'j', '415', '1717', '8999']
Solution: a, f, g, j, k, m, v, x