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: ['m', '9923', '8515', 's', 'y', '3939', 'x', 't', 'c', '3305', 'e', 'j', 'k', '6667', '121', '7799', 'c', 'j', 'c', '3143', 'j', '2261', 'i', 'h', '9571', '2799', 'b', '4873', '6797', 'm', '4085', 'a', 'i', 'd', '317', 'c', '1017', '8591', '1571', '3441', '2393']
Solution:
a, b, c, d, e, h, i, j, k, m, s, t, x, y