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: ['5427', 'q', '9849', '397', 'o', 'k', '4793', 'v', '5081', '5499', 'z', '855', '8619', 't', '1805', '3715', 'k', '8429', 'u', '3061', 'g', 'h', 'z', 'h', '4013', '9813', 'c', 'f', 's', '6379', 'j', 'b', 'o', 'u', '7399', 't', 'i', 'a', '1721', 'r', 'a']
Solution:
a, b, c, f, g, h, i, j, k, o, q, r, s, t, u, v, z