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.
One example: ['8129', 'a', '4245', 'y', 'm', 'a']
Solution is here: a, m, y
Explanation: Here, the unique alphabets in the list are 'a', 'y', and 'm', hence their sorted order is 'a, m, y'.

Now, solve this: ['421', '3513', '1675', '175', 'e', '7233', '8297', '175', 'o', 'e', '9311', '9917', '497', '797', 'u', 'k', '3725', '1513', '1569', 'y', 'k', 'o', '9825', '5137', 't', '575', '6379', 'n', 'y', '227', 'f', '4381', '5221', 'g', 'j', 'f', '8279', 'b', '6895', 'q', 'r', '3869', 'e', 'b']
Solution:
b, e, f, g, j, k, n, o, q, r, t, u, y