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: ['x', '5027', 'f', '51', '6655', 'b', '1741', 'f', '5675', '2613', '7503', '6879', 'u', 'u', 'b', 'j', 'u', 's', '1627', '1505', '3919', '8479', 'a', 'y', '161', '6697', '6327', '1605', '6463', '9513', 'x', 'x', 'g', '1657', '9679', 'k', '1341']
Solution:
a, b, f, g, j, k, s, u, x, y