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.

Let me give you an example: ['8129', 'a', '4245', 'y', 'm', 'a']
The answer to this example can be: a, m, y
Here is why: Here, the unique alphabets in the list are 'a', 'y', and 'm', hence their sorted order is 'a, m, y'.

OK. solve this:
['1785', '2911', '3361', 'e', 'g', '8667', '4061', '8701', 'm', 'd', '8871', '9725', '6125', '6181', '8621', '8709', 'n', '251', '9187', '5823', '5961', '4393', 'c', 'e', 'x', '943', '9091', '6131', '7027']
Answer:
c, d, e, g, m, n, x